WASHINGTON - The Bush administration is conceding for the first time that the United States might not finish a complex security agreement with Iraq before President Bush leaves office.

Because of stiff Iraqi opposition, it is "very possible" the United States may have to extend an existing U.N. mandate, said a senior administration official close to the talks.

That would mean major decisions about how U.S. forces operate in Iraq could be left to the next president, including how much authority the United States must give Iraqis over military operations.

The official said the goal was still to have an agreement by year's end. Even so, Ryan Crocker, the U.S. ambassador to Iraq, said last week: "My focus on this is more on getting it done right than getting it done quick."

The somber assessment came as even a revised draft of the deal failed to gain acceptance among Iraqi parliamentarians. Ayatollah Ali Khamenei, supreme leader of neighboring Iran, also made clear his rejection of the proposed agreement.

Khamenei told visiting Iraqi Prime Minister Nouri al-Maliki that Iraqis must "think of a solution to free" the country from the U.S. military, according to Iranian state-run television.

The Iranians fear the deal would give American forces in Iraq a launching pad for military action against them. Maliki tried to ease Tehran's concerns, assuring the Iranians that a deal would pose no threat to their security.

The Bush administration is seeking an agreement with Baghdad that would provide for a permanent U.S. military and diplomatic presence in Iraq.

The word

permanent

has been a flash point for many in Iraq. But the U.S. official stressed that the agreement would not call for permanent U.S. bases on Iraqi soil.

Instead, the proposed agreement would allow U.S. troops or personnel to operate out of U.S., Iraqi or joint facilities through either short or long-term contracts, said the official, who spoke on condition of anonymity because the negotiations were not public.

U.S. and Iraqi leaders are struggling to negotiate two parallel agreements. One would lay out broad, long-term political, economic and security ties between the United States and Iraq, setting up a normal state-to-state relationship.

The second - and decidedly more difficult pact - is the Status of Forces Agreement that would detail the legal basis for the continuing presence of U.S. military forces operating in Iraq. The agreements would replace a U.N. mandate, in place since the U.S.-led invasion in March 2003, that expires at the end of this year.

The United States and Iraq may have to extend the U.N. mandate because the thorny military details will require more time, the U.S. official said.

Iraqi officials have raised a number of objections to the draft documents.

Yesterday, two Iraqi lawmakers who saw the draft said the document, put forward Sunday, sought to address some of Iraq's concerns. It adds a promise that U.S. forces in Iraq will not attack neighboring countries and that Iraqi authorities will be notified in advance of any action by U.S. ground forces, the lawmakers said.

Also, while it gives U.S. forces power to arrest suspects, it says detainees would be handed over to Iraqi authorities, said the lawmakers, Mahmoud Othman and Iman al-Asadi.

But Hadi al-Amri, head of the Badr Organization, a pro-government Shiite party with close ties to Iran, said the latest draft was still unacceptable.

Air Strike Kills 5 Sunni Militants

American soldiers

called in an air strike yesterday during an attack on a house believed used by foreign fighters, killing five militants and capturing more than

a dozen, the U.S. military said.

The firefight

broke out early yesterday when American soldiers, acting on information from an Iraqi prisoner, came under heavy gunfire as they approached the suspected hideout in a remote area of northwestern Iraq, a

U.S. statement said.

The battle

was among

a series of raids during the last two days in northern Iraq against Sunni militants, who remain active.

- Associated Press