The Bush administration appeared to be caught off guard and somewhat confused yesterday after the Iraqi Governing Council nominated a physician with longtime CIA ties as the post-occupation prime minister. Officials in Washington scrambled to respond after the Iraqis took the public lead in a process that was supposed to be run by a U.N. envoy.

In a telephone conversation at 2:30 p.m., a senior U.S. official involved in Iraq policy sounded uncertain about whether Ayad Allawi would head Iraq's interim government after the United States transfers limited authority on June 30.

"We may or may not have heard the last word on the prime minister," the official said. "You have to put a lot of pieces together first."

A senior administration official in Baghdad said that L. Paul Bremer, the civilian U.S. administrator, and Robert D. Blackwill, the U.S. presidential envoy to Iraq, knew about the impending selection on Thursday. But officials in Baghdad feared a leak and told few officials in Washington. Some members of President Bush's war cabinet knew where the process was heading but were surprised by the timing of the council's decision.

The administration's statements were reserved because the United States did not want to appear to be driving the process, officials said, especially because of the country's past ties with Allawi.

The confusion extended to the United Nations in New York, where chief spokesman Fred Eckhard at first said that the U.N. envoy, Lakhdar Brahimi, had been in the room for the selection by the U.S.-appointed council but then later corrected himself to say that Brahimi had not been there.

"It's not how we expected it to happen," Eckhard told Reuters.

By day's end, Brahimi and Bremer had both endorsed Allawi, and a senior U.S. official in Baghdad said without equivocation that Allawi will take office.

One of the working assumptions among senior foreign policy officials in the Bush administration had been that Iraq's new prime minister, the most important of the 30 jobs to be filled, would not come from the Governing Council. None of the 25 council members, all handpicked by the U.S.-led coalition, has rallied significant popular support, according to several public opinion surveys over the past few months.

In an attempt to ensure that the new government would enjoy a degree of legitimacy in the eyes of Iraq's 25 million people, U.S. officials also thought they needed to find someone who would not be seen as a surrogate of the United States -- representing a "clean break from the occupation," as a diplomat from a coalition country said. Allawi is among those with close U.S. ties, including to the U.S. intelligence community.

During his speech Monday on Iraq, Bush had described how the process was supposed to work. "The United Nations special envoy, Lakhdar Brahimi, is now consulting with a broad spectrum of Iraqis to determine the composition of this interim government," the president said then. "The special envoy intends to put forward the names of interim government officials this week."

Four hours after the council's vote, Bush said during a Rose Garden ceremony that the United States was prepared to "transfer complete and full sovereignty to an Iraqi government that will be picked by Mr. Brahimi of the United Nations."

That was not how the selection emerged. The Associated Press moved its bulletin from Baghdad at 8:26 a.m. Eastern time, saying: "The Governing Council has unanimously endorsed Iyad Allawi to become Iraq's new prime minister." Reuters followed at 8:41 a.m.: "IYAD ALLAWI CHOSEN AS IRAQI PRIME MINISTER -- AIDE TO ALLAWI."

Shortly after 10 a.m., White House press secretary Scott McClellan told reporters: "Mr. Brahimi is the one who will make the determinations about who the representatives are on the interim government."

At an appearance at the State Department's Foreign Press Center that began at 10:22 a.m., Secretary of State Colin L. Powell seemed unsure whether Allawi was a candidate, a nominee or the final choice.

"I think the report you're referring to is a wire service report over the last hour that said that the Governing Council had voted and the result of that vote was that they are recommending or -- nominating is, I think, one of the words they used -- but they are recommending Mr. Allawi for the position of prime minister," Powell said.

Powell said he was "pleased that Mr. Allawi has that kind of support, but we are working with Ambassador Lakhdar Brahimi, the secretary general's representative."

"And so we have no position on any candidate at this moment because we are waiting to hear from Ambassador Brahimi, and he needs time to complete his work," he added.

At a televised briefing that began at 3:02 p.m., McClellan still referred to "news reports on Mr. Allawi" and said the United States was waiting "until we hear more" from Brahimi.

By dinnertime, a senior administration official conceded that there was no mystery about who would be prime minister but emphasized that the United States will not consider the matter official until Brahimi announces the whole slate. "There was clearly an emerging consensus that Allawi was the best choice and the logical choice," the official said. "What we saw today was the Governing Council decided to join that consensus by making their statement."

Correspondent Rajiv Chandrasekaran in Baghdad and staff writer Glenn Kessler in Washington contributed to this report.