Secretary-General Kofi Annan (search) has selected Pakistan's ambassador to Washington for the job of U.N. envoy to Iraq, replacing a top diplomat who was killed in a Baghdad bombing last year.

Ashraf Jehangir Qazi (search), who has served in key posts around the world, was chosen from a short-list of three candidates after extensive consultations, U.N. associate spokeswoman Marie Okabe said.

Annan has had difficulty finding someone for the job. He said last month that several candidates initially said "yes" but then called a week later telling him they had to say "no" because their families objected.

Annan intends to have Qazi based in Baghdad, but the United Nations (search) must get "the sufficient security guarantees from both the Iraqis and from the forces on the ground ... before he can be deployed," Okabe said.

"It's a very challenging job," Pakistani Embassy spokeswoman Tallat Wasim told The Associated Press. "He's looking forward to it."

The other contenders were former Indian Foreign Secretary Salman Haidar and former Thai Foreign Minister Surin Pitsuwan, she said. Like Qazi, they are Muslims.

The new U.N. special representative to Iraq will replace top U.N. envoy Sergio Vieira de Mello (search), who was one of 22 people killed in the Aug. 19, 2003, bombing at U.N. headquarters in Baghdad.

The secretary-general ordered all U.N. international staff to leave Iraq in October following a second bombing at U.N. headquarters and a spate of attacks targeting foreign workers.

Despite the surge in violence in Iraq, Annan has said he expects the new U.N. envoy to be based in Baghdad. But Annan has said he won't allow large numbers of U.N. staff back to return until the security situation improves.

Okabe said Qazi must first be released from his current duties in Washington. He is will then come to U.N. headquarters in New York in a week or two for briefings and consultations. No date has been set for his deployment to Baghdad.

The resolution adopted last month by the U.N. Security Council endorsing the transfer of power to Iraq's new interim government authorized the U.S.-led multinational force to remain in the country to help ensure security.

It also authorized the establishment of a new unit of the multinational force charged with providing security for U.N. staff and facilities. Georgia and Nepal have offered troops for this unit, according to diplomatic sources, speaking on condition of anonymity.

Annan has had difficulty finding a qualified candidate to go to Baghdad to take on the top U.N. job. He said last month that several candidates initially said "yes" but then called a week later telling him they had to say "no" because their families objected.

He had promised a decision by July 2, but the announcement was delayed because Annan, who has been traveling in Africa and Asia, needed to get approval from Pakistani President Gen. Pervez Musharraf, a well-informed U.N. official said, speaking on condition of anonymity.

Qazi, 62, has been ambassador to the United States since September 2002 and previously served as Pakistan's top envoy to India from 1997-2002, to China from 1994-1997, to Russia from 1991-1994, to East Germany from 1990-1991, and to Syria from 1986-1988.