President Barack Obama said Sunday that Israel has “every right” to defend itself against missile attacks by militants inside Gaza but warned that escalating the offensive with Israeli ground troops could undermine any hope of a peace process with the Palestinians.

"Let's understand what the precipitating event here that's causing the current crisis and that was an ever-escalating number of missiles that were landing not just in Israeli territory but in areas that are populated, and there's no country on Earth that would tolerate missiles raining down on its citizens from outside its borders,” Obama said at press conference in Thailand at the start of a three-nation tour in Asia.

“So we are fully supportive of Israel's right to defend itself from missiles landing on people's homes and workplaces and potentially killing civilians."

He added: "Israel has every right to expect that it does not have missiles fired into its territory. If that can be accomplished without a ramping up of military activity in Gaza, that's preferable. It's not just preferable for the people of Gaza. It's also preferable for Israelis, because if Israeli troops are in Gaza, they're much more at risk of incurring fatalities or being wounded."

Netanyahu: Israel prepared for ‘significant expansion’ of Gaza operation

Obama directed some of his comments to the heads of state of Egypt and Turkey, both countries that are supportive of the Palestinians. “Those who champion the cause of Palestinians should recognize that if we see a further escalation of the situation in Gaza than the likelihood of us getting back on any kind of peace track that leads to a two-state solution is going to be pushed off way into the future,” he said.

Obama's comments came as Israel's campaign against Hamas militants in Gaza blasted into its fifth day. Israel is at a crossroads of whether to launch a ground invasion or pursue Egyptian-led truce efforts, and Obama sought to clearly defend the U.S. ally's military rights while pushing for a halt in the violence.

Key players in the Israel-Gaza cross-border conflict

Israeli Prime Minister Benjamin Netanyahu declared Sunday that Israel was prepared to significantly expand its military operation in Gaza. Obama has been lobbying Netanyahu along with the leaders of Egypt and Turkey to try to halt the crisis -- including stopping rocket strikes on Israel.

Slideshow: Israel, Gaza violence escalates

Ammar Awad / Reuters

Two sides exchange deadly airstrikes, rocket attacks.

Launch slideshow

He said Israel was justly responding to "an ever escalating number of missiles that were landing not just in Israeli territory, but in areas that are populated. And there's no country on earth that would tolerate missiles raining down on its citizens from outside its borders."

Obama said Palestinians will have no chance to pursue their own state and a lasting peace with Israel as long as rockets are fired into Israel. He said he hoped for a clearer process over the next 48 hours -- showing how much the Mideast conflict had intruded on his diplomatic mission to Asia.

NBC News' Shawna Thomas and The Associated Press contributed to this story.

More content from NBCNews.com:

• Body found at scene of oil platform explosion in Gulf of Mexico, Coast Guard says
• 6 officers injured when 2 police helicopters collide in Pasadena
• Foul smell leads police to dismembered woman in Southern California
• Large amounts of bomb-making chemicals found in doctor's home, authorities say

Follow US news from NBCNews.com on Twitter and Facebook

Reuters, file

U.S. citizen Rachel Corrie, 23, speaks through a megaphone to an Israeli army bulldozer on the day she was killed in Rafah, in the southern Gaza Strip on March 16, 2003.

HAIFA, Israel -- An Israeli court rejected on Tuesday accusations that Israel was at fault over the death of American activist Rachel Corrie, who was crushed by an army bulldozer during a 2003 pro-Palestinian demonstration in Gaza.

Corrie's family had accused Israel of intentionally and unlawfully killing their 23-year-old daughter, launching a civil case in the northern Israeli city of Haifa after a military investigation had cleared the army of wrongdoing.

In a ruling read out to the court, judge Oded Gershon called Corrie's death a "regrettable accident," but said the state was not responsible because the incident had occurred during what he termed a war-time situation.

At the time of her death, during a Palestinian uprising, Corrie was protesting against Israel's demolition of Palestinian homes in Rafah in the southern Gaza Strip.

"I reject the suit," the judge said. "There is no justification to demand the state pay any damages."

He added that the soldiers had done their utmost to keep people away from the site. "She (Corrie) did not distance herself from the area, as any thinking person would have done."

Oliver Weiken / EPA

Rachel Corrie's parents Craig and Cindy and her sister Sarah, left, are seen prior to the announcement of the verdict at the Haifa district court on Tuesday.

Mom: 'I am hurt'
Corrie's death made her a symbol of the uprising, and while her family battled through the courts to establish who was responsible for her killing, her story was dramatized on stage in a dozen countries and told in the book "Let Me Stand Alone."

"I am hurt," Corrie's mother, Cindy, told reporters after the verdict was read.

Corrie's mother Cindy told a news conference after the court's decision that the bulldozer personnel had the "ability" and also an "obligation" to have seen that her daughter was in its path.

NBC station KING5: 'Rachel Corrie' aid ship boarded by Israelis

She said she hoped the lawsuit would help change Israel's policies regarding the demolition of Palestinian houses.

Cindy Corrie said that previously a senior Israeli soldier had said there were "no civilians in war."

"Rachel was in Gaza because there were and are civilians there, those who have rights and deserve protection," she added. "Rachel's right to life and dignity were violated by the actions of the Israeli military."

She said her daughter was a "rich thinker and a beautiful person" from "Olympia, Washington, USA," her voice breaking as she spoke.

The family's attorney, Hussein Abu Hussein, said that the court's decision was so close to the Israeli government's position that the state's lawyers could have written it themselves, according to The Jerusalem Post.

The U.K.'s Guardian newspaper reported that Corrie was with a group of international activists acting as human shields against the demolition of Palestinian houses.

"She was standing on top of a pile of earth," fellow activist and eyewitness Richard Purssell, from Brighton, U.K., said at the time, according to the Guardian. "The driver cannot have failed to see her. As the blade pushed the pile, the earth rose up. Rachel slid down the pile. It looks as if her foot got caught. The driver didn't slow down; he just ran over her. Then he reversed the bulldozer back over her again."

Few Israelis showed much sympathy for Corrie's death, which took place at the height of the uprising in which thousands of Palestinians were killed and hundreds of Israelis died in suicide bombings.

Getty Images / Getty Images, file

Rachel Corrie speaks during an interview with MBC Saudi Arabia television on March 14, 2003 in the Rafah refugee camp in the Gaza strip.

Corrie was from Olympia, Washington, and was a volunteer with the pro-Palestinian International Solidarity Movement.

Senior U.S. officials criticized the original military investigation into the case, saying it had been neither thorough nor credible. But the judge said the inquiry had been appropriate and pinned no blame on the army.

Reuters contributed to this report.

More world stories from NBC News:

• Marines punish three for urinating on Taliban corpses
• Afghan soldier kills 2 Americans; official disputes accidental claim
• Botched restoration turns Spanish church into tourist attraction
• Afghan sources: Top Haqqani commander killed
• Bulldozer wrecks Sufi mosque and graves in Libya sectarian attack
• Dozens killed, hurt in Venezuela oil refinery explosion
• Syria VP Al-Sharaa appears in public, ending defection rumor

Follow World News from NBCNews.com on Twitter and Facebook

AP

Obada Mzaik, seen in this undated family photo provided by Dr. Firas Nashef, has been missing nearly three weeks after traveling to Syria on Jan. 3, according to relatives.

A 21-year-old Syrian-American has been missing for three weeks after returning to Syria from suburban Detroit, according to a family member in Michigan.

Obada Mzaik flew to Damascus from Detroit Metropolitan Airport on Jan. 3, but wasn't seen leaving an immigration checkpoint, Dr. Firas Nashef, his uncle in Farmington Hills, said.

Mzaik, who was born in Columbus, Ohio, was planning to study civil engineering at Al-Yarmouk University.

He had been temporarily living in the Detroit area with a younger brother while taking fall classes at Oakland Community College, Nashef said.

The brother, Obaie Mzaik, 19, who was on the same flight, was not detained in Damascus, Nashef said.

"We have no idea what happened," the dentist said.

• Russia: We can do no more for Syria's Assad

"It's horrendous because knowing what we know about the prison system over there, anything goes," Nashef told the Detroit News Monday. "The prison system and justice system over there is not very impressive."

He added that Mzaik had been detained in Syria for 37 days last year, but had not been charged officially.

The State Department said it was aware of the matter and was working with authorities in Syria.

On Jan. 11, the U.S. government urged Americans to get out of Syria and to avoid any travel there.

• More of msnbc.com's Syria coverage

Mzaik has citizenship in the U.S. and Syria. Nashef said the family returned to Syria in 1994 when his nephew was about 3.

"Most of his life he's been in Syria," Nashef said.

'Deep concern'
The Detroit News noted that a Facebook page, entitled "Freedom to our friend Obada Mzaik," has been set up.

It had 1,220 likes as of early Tuesday morning.

A link on that page led to a petition on the www.change.org website, which urges the State Department to help free Mzaik.

• NBC's Ayman Mohyeldin answers reader questions from Syria

"As Syrians looking for freedom, we are outraged by the obscure circumstances surrounding Obada's arrest, and we express our deep concern over his safety in the Syrian regime's custody," the petition says.

One message, which msnbc.com was immediately unable to verify, says "because he is my son ... I want him free and now."

The Associated Press contributed to this report.

Updated at 6:10 p.m. ET

President Barack Obama stopped short of calling the U.S. effort in Iraq a victory in an interview taped Thursday with ABC News' Barbara Walters.

"I would describe our troops as having succeeded in the mission of giving to the Iraqis their country in a way that gives them a chance for a successful future," Obama said.

Iraqi citizens offered a more pessimistic assessment. "The Americans are leaving behind them a destroyed country," said Mariam Khazim of Sadr City. "The Americans did not leave modern schools or big factories behind them. Instead, they left thousands of widows and orphans."

The Iraq Body Count website says more than 100,000 Iraqis have been killed since the U.S. invasion. The vast majority were civilians.

Updated at 10:58 a.m. ET

BAGHDAD --  U.S. forces formally ended their nine-year war in Iraq with a low-key flag ceremony in Baghdad on Thursday.

"After a lot of blood spilled by Iraqis and Americans, the mission of an Iraq that could govern and secure itself has become real," Defense Secretary Leon Panetta said at the ceremony at Baghdad's still heavily fortified airport.

• Vote: How would you describe the war in Iraq?

Almost 4,500 U.S. soldiers and tens of thousands of Iraqis lost their lives in the war that began with a "Shock and Awe" campaign of missiles pounding Baghdad and descended into sectarian strife and a surge in U.S. troop numbers.

U.S. soldiers lowered the flag of American forces in Iraq and slipped it into a camouflage-colored sleeve in a brief outdoor ceremony, symbolically ending the most unpopular U.S. military venture since the Vietnam War of the 1960s and 70s.

Iraqi Prime Minister Nouri al-Maliki and President Jalal Talabani were invited to the ceremony but did not attend.

In addition to the dead, the war left 32,000 Americans wounded and cost the U.S. more than $800 billion.

• PhotoBlog: Symbolism and souvenirs at ceremony

The remaining 4,000 American troops will leave by the end of the year.

Bombings are still common. Experts are also concerned about the Iraqi security force's ability to defend the nation against foreign threats.

However, Panetta said veterans of the conflict can be "secure in knowing that your sacrifice has helped the Iraqi people to cast tyranny aside."

• NYT: Junkyard's secret account of massacre

Some Iraqi citizens offered a more pessimistic assessment. "The Americans are leaving behind them a destroyed country," said Mariam Khazim of Sadr City. "The Americans did not leave modern schools or big factories behind them. Instead, they left thousands of widows and orphans."

Gen. Lloyd Austin, the top U.S. commander in Iraq, and Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, also spoke during the ceremony.

• PhotoBlog: Troops head for home

Updated at 5:46 a.m. ET: Austin says Iraqis now have "unprecedented opportunities."

Updated at 5:42 a.m ET: "Since 2003, we have helped the Iraqi security forces grow from zero to 650,000-strong," Austin says.

Updated at 5:40 a.m. ET: Austin recalls how he was present when American forces secured the airfield where the ceremony is being held. "After 21 days of tough fighting, we ended Saddam Hussein's reign of terror," he adds.

Updated at 5:37 a.m. ET: Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, points out that the next time he visits Baghdad it will have to be at the invitation of the Iraqi government. "I kinda like that," he adds.

Updated at 5:32 a.m. ET: "This is not the end, this is the beginning," Panetta says. "May God bless Iraq, its people and its future."

NBC News

U.S. troops take part in the end of mission ceremony in Baghdad, Iraq, on Thursday.

Updated at 5:29 a.m. ET: "Let me be clear, Iraq will be tested in the days ahead -- by terrorism, by those who would seek to divide," Panetta says. "Challenges remain but the United States will be there to stand with the Iraqi people. We are not about to turn our backs on all that has been sacrificed and accomplished."

Updated at 5:26 a.m. ET: "Your sacrifice has helped the Iraqi people begin a new chapter in history, free from tyranny," Panetta says. "This outcome was never certain, particularly during the war's darkest days."

Updated at 5:23 a.m. ET: Panetta highlights the "heartbreak" of military families who watched their loved ones go off to war.

Updated at 5:18 a.m. ET: "It is a profound honor to be here in Baghdad," Panetta says at ceremony."No words, no ceremony can provide full tribute to the sacrifices that have brought this day to pass."

Updated at 5:16 a.m. ET: "We look forward to an Iraq that is sovereign, secure and self-reliant," US Ambassador to Iraq James Jeffrey says.

Published at 4:45 a.m. ET: After nearly nine years, 4,500 American dead, 32,000 wounded and more than $800 billion, U.S. officials prepared Thursday to formally shut down the war in Iraq — a conflict that U.S. Defense Secretary Leon Panetta said was worth the price in blood and money, as it set Iraq on a path to democracy.

Panetta stepped off his military plane in Baghdad Thursday as the leader of America's war in Iraq, but will leave as one of many top U.S. and global officials who hope to work with the struggling nation as it tries to find its new place in the Middle East and the broader world.

He and several other U.S. diplomatic, military and defense leaders will participate in a highly symbolic ceremony during which the flag of U.S. Forces-Iraq will officially be retired, or "cased," according to Army tradition.

During several stops in Afghanistan this week, Panetta made it clear that the U.S. can be proud of its accomplishments in Iraq, and that the cost of the bitterly divisive war was worth it.

"We spilled a lot of blood there," Panetta said. "But all of that has not been in vain. It's been to achieve a mission making that country sovereign and independent and able to govern and secure itself."

That, he said, is "a tribute to everybody — everybody who fought in that war, everybody who spilled blood in that war, everybody who was dedicated to making sure we could achieve that mission."

Panetta has echoed President Barack Obama's promise that the U.S. plans to keep a robust diplomatic presence in Iraq, foster a deep and lasting relationship with the nation and maintain a strong military force in the region.

As of Thursday, there were two U.S. bases and about 4,000 U.S. troops in Iraq — a dramatic drop from the roughly 500 military installations and as many as 170,000 troops during the surge ordered by President George W. Bush in 2007, when violence and raging sectarianism gripped the country. All U.S. troops are slated to be out of Iraq by the end of the year, but officials are likely to meet that goal a bit before then.

Read more about the Iraq withdrawal

• Post-US Iraq: Welcome to Shia-stan
• Iraqis unable to defend borders as US exits
• Iraqi voices: Patchwork electrical grid a symbol of country's disconnects
• Iraqi voices: Colonel helped with surge, then his past came calling
• A special homecoming from Iraq

The total U.S. departure is a bit earlier than initially planned, and military leaders worry that it is premature for the still maturing Iraqi security forces, who face continuing struggles to develop the logistics, air operations, surveillance and intelligence sharing capabilities they will need in what has long been a difficult neighborhood.

U.S. officials were unable to reach an agreement with the Iraqis on legal issues and troop immunity that would have allowed a small training and counterterrorism force to remain. U.S. defense officials said they expect there will be no movement on that issue until sometime next year.

Still, despite Obama's earlier contention that all American troops would be home for Christmas, at least 4,000 forces will remain in Kuwait for some months. The troops will be able to help finalize the move out of Iraq, but could also be used as a quick reaction force if needed.

Bombings and attacks have eased since American and Iraqi security forces weakened insurgents. But roadside bombs, car bombs and assassinations still kill and maim almost every day.

A frail economy, constant power shortages, scarce jobs and discontent with political leaders all fuel uncertainty among Iraqis.

"Thanks to the Americans. They took us away from Saddam Hussein, I have to say that. But I think now we are going to be in trouble," said Malik Abed, 44, a vendor at a Baghdad fish market. "Maybe the terrorists will start attacking us again."

Read more content from msnbc.com and NBC News:

• Post-US Iraq: Welcome to Shia-stan
• Nazi hunters boost drive to find aging war criminals before they die
• Pakistan opposition leader: War on terror creating extremists
• Wild monkeys to detect radiation at Fukushima
• North Korea's heir apparent's hair apparent as fashion hit
• UN chief defends NATO, calls for action on Syria
• Rebellious Chinese village under siege by police
• Iraqis unable to defend their borders as US exits

The Associated Press, Reuters, NBC News and msnbc.com staff contributed to this report.