The U.S. weekly news magazine "Time" quotes Khalilzad as saying he hopes to persuade the various factional leaders to participate in such a conclave.
Iraq's new parliament is due to hold its first meeting on March 19, a week later than spelled out in the constitution. Factions remain deeply divided over how to fill the prime ministerial post and other vacancies.
Members of the dominant Shi'ite United Iraqi Alliance (UIA) have reelected outgoing Prime Minister Ibrahim al-Ja'fari as their candidate to head the cabinet. But Sunnis and Kurds, including President Jalal Talabani, have sought to veto a second term for al-Ja'fari.
Khalilzad also says he believes a significant pullout of U.S. troops this year remains a possibility. The United States has stressed that the political process in Iraq must advance quickly, so that the new government can deal with the country's deteriorating security situation.
