Al-Jadaan was a leader of the Karabila tribe, which has thousands of members in Anbar province, an insurgent hotbed stretching from west of Baghdad to the Syrian border. He had announced an agreement with the U.S.-backed Iraqi government to help security forces track down al-Qaida members and foreign fighters.

Meanwhile, the country's parliament met Monday to discuss the tenuous security situation.

U.S. officials hope Iraqis will be able to take on more security duties soon, allowing American forces to begin pulling out. But a week after Prime Minister Nouri al-Maliki's unity government took office, Iraq's ethnic, sectarian and secular parties are struggling to agree on who should run the crucial interior and defense ministries, which control the various Iraqi security forces.

The impasse dashed hopes that al-Maliki, a member of Iraq's Shiite majority, could swear in the two new ministers when the 275-member parliament convened Sunday after a four-day recess.

Al-Maliki's spokesman, Yassin Majid, said if negotiations took much longer, the prime minister would ask the political blocs to present three names for each ministry so he could decide.

"There is no deadline for that, but it could happen this week," Majid said.

Hassan al-Sineid, a Shiite legislator who belongs to al-Maliki's Dawa Party, said that step might come by Wednesday.

The Shiite-dominated interior ministry, which controls the police forces, has been promised to that community. Sunni Arabs are to get the defense ministry, overseeing the army.

It is hoped the balance will enable al-Maliki to move ahead with a plan for Iraqis to take on all security duties over the next 18 months. He wants to try to attract army recruits from among the Sunni Arab minority, which provides the core of the insurgency.