Iraq Troop Withdrawal: Obama Marks Milestone Amid Today's Violence

4 U.S. troops were killed on the eve of the American pullout from Iraqi cities.

Four U.S. soldiers were killed in combat Monday on the eve of the pullout by American troops from Baghdad and other Iraqi cities, the U.S. military said.

The military said the four soldiers served with the Multi-National Division-Baghdad and died as a "result of combat related injuries," but did not provide further details pending notification of their families.

Meanwhile, a car bomb exploded Tuesday in the northern Iraqi city of Kirkuk, killing 30 people and wounding nearly 90 more in a crowded market, according to medical sources in Kirkuk.

"We know that the violence in Iraq will continue," President Barack Obama said from the White House today, referencing the bombing in Kirkuk. "There are those who will test Iraq's security forces and the resolve of the Iraqi people through more sectarian bombings and the murder of innocent civilians. But I'm confident that those forces will fail. The future belongs to those who build, not those who destroy."

The attacks come as Iraqis celebrate the withdrawal of U.S. troops from 15 cities, the first milestone in a U.S.-Iraqi security agreement that calls for the departure of all U.S. troops by the end of 2011.

The president called the day a significant milestone, marking progress and responsibility for the Iraqi people. He referenced the celebration in Baghdad as a positive sign and a symbol of U.S. forces' courage in the region.

"The Iraqi people are rightly treating this day as a cause for celebration. This is an important step forward as a sovereign and united Iraq continues to take control of its own destiny," Obama said. "Iraq's future is in the hands of its own people, and Iraq's leaders must now make some hard choices necessary to resolve key political questions, to advance opportunity and to provide security for their towns and their cities."

The top U.S. commander in Iraq, Gen. Ray Odierno, added today that while the last two weeks were marked by an increase in violent attacks, the overall numbers are still down from two years ago.

"If you compare it back to the dark days of 2006 and 2007, there's no comparison," Odierno told reporters Monday. "There is not widespread violence here in Iraq. There are points of high-profile attacks. The unfortunate part about that is… it has inflicted some high casualties on the civilian population here."

Odierno, says it's time for Iraqis to take charge and responsibility inside the cities.

"The Iraqi people want their forces to take that on," he said. "They want to see us move out of the cities. ... in the background. They're not ready for us to go yet, but they are ready for us to allow them to attempt to exercise their security responsibilities."

But some are not convinced.

Former Vice President Dick Cheney, who has recently become a leading critic of the Obama administration's national security policies, applauded Odierno's work in Iraq, but said he was concerned about the withdrawal, even though it was during his time as vice president that the two countries signed the Status of Forces Agreement.

"What he says concerns me: That there is still a continuing problem. One might speculate that insurgents are waiting as soon as they get an opportunity to launch more attacks," Cheney said in an interview with The Washington Times' "America's Morning News" radio show. "I hope the Iraqis can deal with it. At some point they have to stand on their own, but I would not want to see the U.S. waste all the tremendous sacrifice that has gotten us to this point."

The withdrawal and security agreement was negotiated in the last months of the Bush administration, and upon assuming office, President Obama approved a troop withdrawal schedule that will lead to the end of the combat mission by Aug. 31, 2010.

At that point a remaining force of 35,000 to 50,000 American forces in Iraq will continue to serve on as military trainers and advisers until the final pullout date by the end of 2011.

Iraqis Mark U.S. Pullout With Holiday

Fireworks lit up the night sky over Baghdad Monday night in celebration as a countdown clock broadcast on Iraqi TV ticked to zero at midnight. Iraqis are planning a parade and other festivities today in Baghdad's Green Zone district, which to many locals has become the symbol of foreign military presence since the 2001 U.S. invasion.

The date has long been anticipated by Iraqis, and Prime Minister Nouri al Maliki declared Tuesday a public holiday: National Sovereignty Day.

"I congratulate the Iraqi people on this day, June 30, when the U.S. forces have withdrawn from Iraq cities in accordance to the forces withdrawal agreement," al-Maliki said in a televised speech. "We consider this day as a national holiday and it is a joint achievement by all Iraqis."

Prominent Shiite lawmaker and parliament member Abbas Al Bayati told Al Iraqia television that "The day of June 30th is the day of unity among the political blocs for standing behind the national unity government."

Under the Status of Forces Agreement, Iraqi forces were to assume formal control of security in Baghdad and Iraq's major cities as U.S. combat troops withdrew to areas outside the cities by June 30.

More than 130,000 U.S. soldiers -- just slightly less than the 145,000 at the time of the invasion -- still remain in Baghdad. U.S. troops will still have a presence in the cities from where they are withdrawing, but they will serve as embedded trainers with Iraqi army and police units. Additional forces will continue to provide logistical assistance to Iraq's troops in the cities.

Camp Victory Will Remain Open in Western Baghdad

The bulk of U.S. troops will continue to operate in Iraq's rural areas and the belts surrounding urban areas in joint patrols with Iraqi security forces, much as they have since the security framework was put in place early this year.

Quick Reaction Forces will also be ready at U.S. bases outside the cities to assist forces that might need help, but they will enter the cities only if invited by Iraqi authorities.

In preparation for the withdrawal from the cities, the United States has closed or turned over to Iraqi authorities nearly 150 U.S. camps or facilities since the start of this year.

The remaining 310 U.S. facilities will be reduced in number over the next two years as the United States continues on the path of pulling all of its forces out of the country by Dec. 31, 2011, as required by the security agreement.

However, both the United States and Iraq agreed that large American bases inside Baghdad and Mosul, like the sprawling facility in western Baghdad known as Camp Victory, would be exempted from the agreement, given their large size and their importance to the overall security mission in Iraq.

The troop drawdown in Iraq won't pick up momentum until next year because Odierno wants to have enough troops on hand to provide security for the all-important Iraqi national elections to be held this coming January.

There are 133,000 U.S. troops currently in Iraq, and will likely be 120,000 to 125,000 by year's end to provide security for the election.

After the election, the U.S. drawdown will begin in earnest. By August 2010, the number of troops is supposed to be cut by almost 70,000 to meet the reduced force level that will remain as trainers.

The accelerated drawdown next year will pose major logistical challenges for a military that has accumulated a large amount of equipment and facilities in Iraq since the U.S. invasion in 2003.

Though U.S. military leaders were confident of meeting the deadline as late as this April, senior military commanders, like Odierno, had expressed reservations about whether a pullout might be feasible from the restive northern city of Mosul, given the strong insurgency there that contributed to continuing high levels of violence.

But Odierno said that the decision to proceed was made easier by violence levels in May that were the "lowest level of incidents we've ever had on record in Iraq," a trend that has continued through June despite several high-profile attacks this past week.

"I would just say, though, there's still going to be bumps in the road," Odierno said. "There's still going to be violence here. There's still going to be some problems."

The general said that the attacks, especially those instigated by al Qaeda in Iraq, have turned the Iraqi population against insurgents, which will make it more difficult for them to operate in the future.

"I believe that's going to backfire on them over time," the general said. "They've really raised the ire of the Iraqi citizens."

Despite words of hope and the jubilation among Iraqis and the confidence of U.S. commanders, U.S. troops know their work is not yet finished and more sacrifices lie ahead.

Lt. Colonel Tim Karcher, a father of three who just 10 days ago handed over command of Sadr City -- one of Baghdad's most violent neighborhoods -- to Iraqis, lost both his legs and is struggling for his life after a bomb shattered his vehicle just days ago.

Karcher is still at Landstuhl, a medical center in Germany, but his wife Alesia told ABC News he is expected to arrive at Walter Reed Army Medical Center in Washington, D.C., this weekend.

"I don't know what is in store for him, but I know he will use this to do something good. I expect he will be using prosthetics and running and doing whatever his heart desires," said his wife of 19 years. "He is the most wonderful person I have ever met...He is strong and the only thing that is going to make him upset when he wakes up is that he is not with his soldiers."

As a senior official told ABC News: "This war continues."

ABC's Aadel Rashid in Baghdad, ABC's Yunji de Nies at the White House and The Associated Press contributed to the reporting of this story.