President Bush said Monday the United States has made some missteps in Iraq but that his decision to send in American troops to topple Saddam Hussein was the right call.

"On the big decisions of sending the troops in, I'd have done it again," Bush told a questioner after a speech here on immigration.

Bush said a new democracy is arising in Iraq where there once was tyranny. Over the weekend, Bush talked with Iraqi leaders who were named Saturday to form a coalition government.

"Each one of them said, 'We want to have a national unity government. We're sick of the sectarian violence. We believe if you stand with us, we can achieve our objective of becoming a democracy that listens to the people,"' Bush said.

"And I believe them. And I believe them. And I told them, I said, 'Look, it's going to be up to you to make it work, but you can count on the United States of America, because we believe in liberty and the capacity of liberty to change lives and to change a neighborhood for a more peaceful tomorrow."'

Bush's comments were echoed by Secretary of State Condoleezza Rice, who said Iraq's new leadership provides the best opportunity to rein in rival militia groups blamed for a furious surge in sectarian killings.

Jawad al-Maliki, the Shiite politician selected as Iraq's prime minister Saturday after months of political infighting, is the strongest political figure to emerge since the U.S.-led invasion more than three years ago, she said.

"He comes to this as the strongest political figure really ever ... since the liberation of Iraq," Rice said. "He comes with both the imprimatur of the Iraqi people and ... the mandate to form a unified national unity government."

As for the problem of sectarian violence, Rice said there "the potential for those militias to be an even bigger problem is there."

"But the while the problem of the militias is there and perhaps more urgent, it is also true that for the first time the Iraqis actually have a framework in which to deal with those militias," Rice said en route to diplomatic visits to Greece and Turkey.

Bush's approval rating is at the lowest point of his presidency, and the daily tide of bad news from Iraq — beheadings and suicide bombings among Iraqis and deadly sneak attacks on U.S. soldiers — is a major reason.

Reflecting on the U.S. deployment in Iraq, now in its fourth year, Bush said the United States misjudged the internal security threat and mistakenly attempted big reconstruction projects that became a target for insurgents.

"The fundamental question on the Iraq theater, though, is: Did we put enough troops in there in the first place? That's the debate in Washington," he said. "I'm sure you've heard about it."

He said he told now retired Gen. Tommy Franks, who developed and executed the Iraq invasion plan, "You design the plan and you've got what you need."