UNITED NATIONS – The American ambassador to Iraq, Zalmay Khalilzad, will have an easy Senate confirmation once the White House decides, as expected, to nominate him to head the American mission to Turtle Bay, Washington sources say.

The most senior Muslim official in President Bush’s administration, Mr. Khalilzad has long been considered the top candidate to fill the vacancy left when John Bolton decided last month to forgo a congressional confirmation battle and leave Turtle Bay.

Several Washington sources yesterday confirmed reports that the White House has decided to name Mr. Khalilzad to the U.N. post. The move was seen as a major reshaping of Mr. Bush’s foreign-policy team, as the president prepares to present his new Iraq policy in a major address later this month.

The White House is expected to announce today the nomination of National Intelligence Director John Negroponte to become deputy secretary of state. A retired vice admiral, Michael McConnell, who is a 25-year intelligence veteran, is expected to replace Mr. Negroponte as the nation’s top spy. The ambassador to Pakistan, Ryan Crocker, is expected to replace Mr. Khalilzad in Iraq.

“They don’t want to announce all of this in one package,” one Senate aide said, referring to the thinking in the White House. Once sent to the Senate, he added, the confirmation of Messrs. Negroponte and Khalilzad will be easy to conclude successfully.

“Democrats will take shots at Bush’s Iraq policy, but these guys went through this process so many times, they will have no problem,” the aide said, asking for anonymity because no official confirmation of the nominations had come out.

Mr. Khalilzad replaced Mr. Negroponte as ambassador in Baghdad in the spring of 2005. Before he was posted in Iraq, Mr. Negroponte, a career diplomat, served as America’s ambassador to the United Nations.

Born in Mazar-e- Sharif, Afghanistan, in 1951, Mr. Khalilzad served in various Pentagon and foreign-policy roles under Presidents Reagan, George H.W. Bush, and George W. Bush. In between Republican administrations, he was active in conservative think tanks like the Rand Corporation.

In 1998, along with Mr. Bolton, William Kristol, Richard Perle, Donald Rumsfeld, James Woolsey, and others, he wrote a letter to President Clinton, urging “the removal of Saddam Hussein’s regime from power.” When Mr. Bush won the 2000 election, Mr. Khalilzad was tapped to head the new administration’s transition team for the Defense Department, and later served as top adviser to Defense Secretary Rumsfeld.

His background as a Pashtun-speaking Sunni Muslim became a major asset in Mr. Khalilzad’s career after September 11, 2001, when it became clear that the terrorists were based in his homeland. In November 2003, he became America’s first ambassador to the newly liberated Afghanistan.

After serving in Baghdad since June 2005, several sources who talked to Mr. Khalilzad as early as last summer, told The New York Sun that he “wants out” and that he had eyed the U.N. post, where Mr. Bolton’s tenure ended when a handful of Senators blocked a vote on his nomination.