President Bush said Friday that militias are the biggest roadblock in Iraq's effort to get a unity government up and running, suggesting that sectarian strife may have become a larger problem than the insurgency fed by Saddam loyalists or foreign terrorists.

In addition to widespread attacks by Sunni Arab-led insurgents, Baghdad is rife with Shiite militias and death squads that carry out sectarian reprisal killings. To curb sectarian violence, Iraq's government plans to restructure police in the capital under the newly formed National Police force.

"Perhaps the main challenge is the militia that tend to take the law into their own hands, and it's going to be up to the government to step up and take care of that militia so that the Iraqi people are confident in the security of their country," Bush said.

"It's important to have a secure Iraq in order for people to go about their daily lives," he said.

Bush, whose popularity has suffered from the slow progress in Iraq, spoke at the White House, where he met with 10 former secretaries of state and defense from both Republican and Democratic administrations.

Just over a third of Americans say they support Bush's handling of Iraq more than three years after the U.S.-led invasion, according to AP-Ipsos polling in early April.

U.S. officials hope the new unity government of Shiites, Kurds and Sunnis can win public confidence and in time quell the violence so that American and other international troops can go home.

The framework of the government was put in place last month with the appointment of Nouri al-Maliki as prime minister-designate. Al-Maliki, a Shiite, is trying to put together a Cabinet, but the process has bogged down over who will lead the defense and interior ministries.

"I've got great hopes about this unity government," Bush said. "We've got a Shia as the prime minister-designee, a Sunni as the speaker, a Kurd as the president, all of whom have dedicated themselves to a country moving forward that meets the hopes and aspirations of the Iraqi people."

After a nearly one-hour briefing from Secretary of State Condoleezza Rice and Defense Secretary Donald Rumsfeld, the former officials talked with Bush mostly about Iraq, but also about Iran and the broader Middle East.

"We've had our disagreements in this country about whether or not we should be there in the first place," Bush said. "Now the fundamental question is how do we achieve our objective, which is a democracy which can defend itself, sustain itself — a country which is an ally in the war on terror and a country which serves as a powerful example for others who desire to be free."

Madeleine Albright, President Clinton's secretary of state, who has criticized Bush's decision to invade Iraq, said the meeting was not as stiff as the one Bush had with the former secretaries in January, a gathering that ended with a photo-up in the Oval Office.

"We had quite a bit of give and take," Albright said, adding that she got the sense that there might be more meetings in the future.

Albright said she congratulated Bush on his work to get a peace deal in Sudan, but she said the two clearly disagree about U.S. policy in Iraq and Iran. On Thursday, she said the U.S. should seek direct talks with Iran.

On Iraq, Albright said she agrees with the president that the militias are the biggest challenge.

"We have to figure out a way to get out of this mess. I told him a little bit about the right and left working together — this came up on Sudan," she said. "I was not afraid to tell the president my views."

William Cohen, a defense secretary for Clinton who returned from the Middle East on Thursday night, said Bush solicited the group's opinions on Iran but focused on Iraq. Cohen wouldn't disclose details of the discussion, but he said he was convinced that Bush found it helpful.

Cohen said he learned on his trip that there continues to be concern in the region about slow political progress in Iraq. He said there is apprehension that U.S. troops will be pulled out before Iraq is stable and worry about Iran's nuclear ambitions.

Cohen said he thinks it's premature for the Bush administration to have one-on-one talks with Iran, yet he thought that engagement on lower levels could be maintained.