Friday there were demonstrations in Iraq's Shiite holy city, Najaf, by disciples of cleric Moqtada al-Sadr. Najaf remains surrounded by 2,500 U.S. troops who are threatening to move on the city, risking widespread anger by Iraq's majority Shiite community, if negotiations with the cleric fail to end a two-week uprising by his followers who oppose the U.S. led occupation.

Efforts to end the standoff have put the United States in rare, direct contact with Iran. Coalition spokesman Dan Senor told reporters the Iranian government asked for and got a meeting with an American diplomat posted in Baghdad, but the Tehran government was told not to intervene in the standoff.

"We had a firm message for the Iranians across the board with regard to their role in Iraq, which is to be constructive, not destructive," he said. "There is no role for the Iranians, from our perspective, in the Sadr situation and, in fact, we believe that the issue with Sadr and his militia should be resolved by Iraqis."

As he addressed his followers Friday, Moqtada al-Sadr warned coalition forces of the consequences of a confrontation and denounced plans for the country's political transition, saying sovereignty can only be restored through a popular vote.

But after meeting with British Prime Minister Tony Blair, President Bush vowed to finish the job in Iraq, telling reporters at the White House the coalition will not waver in the face of fear and intimidation.

"And that's why when we say something in Iraq, we're going to do it because we want there to be a free society," he said.

He and Prime Minister Blair endorsed a tentative plan outlined by U.N. envoy Lakhdar Brahimi for a transfer of power after June 30.

"The idea will be to have a broad-based government and then next year to move to a new constitution and then finally to democratic elections," he said.

But that plan must still be put to a vote in the U.N. Security Council, and the United Nations is warning the tentative steps for how Iraq will be governed after June 30 could be jeopardized if the current level of violence continues.