U.S. officials are giving a cautious welcome to reports that radical Iraqi Shi'ite cleric Moqtada al-Sadr will end his rebellion in Najaf. The militia leader pledged to disarm in a letter to the national political conference in Baghdad.

U.S and Iraqi forces have engaged in two weeks of fighting with Moqtada el-Sadr's militia in Najaf, and have been poised for a possible final assault against his so-called "Mahdi Army." And officials here are making clear they would welcome the reported arrangement, under which the al-Sadr forces would disarm and leave the historic Imam Ali Mosque, which has been endangered by the fighting.

At a news briefing, State Department Deputy Spokesman Adam Ereli said the terms that were put to Mr. Al-Sadr and his followers by Iraq's interim government, to disarm and participate peacefully in the country's political process, are clear. He said the Bush administration is hopeful the deal will be fulfilled, yet skeptical given Mr. Al-Sadr's record of violent behavior since the ouster of Saddam Hussein last year.

"The actions we've seen certainly don't point to peaceful expression of dissent," he noted. "There's a long history of violence and resistance to governmental authority by these militia. The government of Iraq has made it clear that this kind of behavior has no place in the new Iraq, and they're acting I think decisively in response to it."

The fighting in Najaf has raged in neighborhoods and a huge cemetery near the historic mosque, where Mr. Al-Sadr and many of his followers are holed up. U.S. forces have been ordered not to fire in the direction of the thousand-year-old shrine regardless of provocation, and spokesman Ereli said Iraqi authorities are solely responsible for its disposition.

Asked if U.S.-led forces would heed a government request to withdraw from Najaf as part of a deal ending the standoff in the city, Mr. Ereli gave no direct reply.

He said without getting into any specific scenario, all security operations of the coalition are performed "consistent with the needs, and desires, of the Iraqi government."