Pakistan's ambassador to Washington, Ashraf Jehangir Qazi, was named yesterday as the new U.N. special representative to Iraq by Secretary General Kofi Annan. The appointment comes amid growing U.S. concern that the U.N. contingent Qazi will lead will be too small to effectively oversee Iraq's fragile political transition.

U.S. officials fear that the United Nations may not have sufficient personnel in Iraq to fulfill an ambitious agenda in the brief time allotted. Qazi will initially head a team of just over 20 staff members, a small fraction of the roughly 600 that the United Nations had posted in Iraq until two suicide bombings at U.N. headquarters in Baghdad last year led to a withdrawal of all non-Iraqi staff.

Qazi, 62, will become the senior foreign adviser in Iraq for the transition's next phase, now that the U.S.-led authority headed by L. Paul Bremer has been dissolved. Although it still has 140,000 troops in Iraq, the United States has ceded significant ground to the United Nations, asking it to lead in preparing a national conference set for this month and in helping Iraqis write a new constitution, hold two elections and conduct a referendum.

"The task of my mission will be to assist the interim government in Iraq to reach its objective of a constitutionally elected government by 2006 and enable Iraq to become a stable democratic government and overcome the suffering that has been its lot for so long," Qazi said yesterday. He will also oversee a major part of reconstruction and humanitarian projects in Iraq.

The appointment of a top U.N. diplomat for Iraq had been delayed as the United Nations struggled to find someone both qualified and willing to take the position. The veteran envoy -- who has served as Pakistan's ambassador in Russia, China, Syria and East Germany and as high commissioner to India -- will fill a job vacant since the car bombing in August that killed U.N. special representative Sergio Vieira de Mello and more than 20 other U.N. employees in Baghdad.

The Bush administration welcomed the appointment. "We'll do everything possible to support his efforts, to work with him and the Iraqi government, and also to take care of things like assisting them with security," said State Department spokesman Richard Boucher.

But Washington is also quietly pressing the United Nations to beef up its presence for fear that deadlines for the political transition will be missed because of the delegation's size. "Ever since they left in 2003, we've encouraged them to go back. We understand the difficult dilemma, but we want them to go back as fast as possible. Any step in that direction is a positive development," said a senior State Department official who spoke on condition of anonymity because negotiations are ongoing. "The more they can put in, the better."

Because of security concerns, Qazi may commute to Baghdad until the situation calms down, U.S. and U.N. officials said. "The security situation is uppermost. As soon as it allows, I hope to be based in Baghdad," Qazi said.

A small U.N. team will travel to Baghdad ahead of Qazi to prepare for Iraq's national conference, scheduled for July 25 to 27, although U.S. officials are warning of problems and a possible delay. The conference, of tribal and provincial leaders, professionals, academics and others, will select about 100 Iraqis for an interim national council. It will not legislate but will be able to question and monitor the country's interim government.

Qazi will be joined by a larger team, which will include 10 electoral experts, a human rights specialist, and several security and humanitarian relief officials, according to senior U.N. officials. One problem in expanding the mission, a senior U.N. official said, is that Washington has cautioned that accommodations are limited.

The United Nations will expand its presence only after a U.N. protection force is created, officials said. Annan has asked several countries, including Pakistan, Ukraine, Bangladesh, Georgia, Nepal and Finland, to participate in a force of more than 3,000. Nepal, Georgia and Ukraine are the only three to pledge troops, but not in large numbers, say U.N. diplomats.

Qazi, who officials expect will travel to Iraq before the end of the month, has been Pakistan's top diplomat in Washington since September 2002. In addition to wide experience in Europe and Asia, he also served as a junior diplomat in Egypt and Libya. A Muslim, he speaks conversational Arabic.

During his Washington tour, Qazi was enmeshed in the flap over allegations that Pakistan assisted North Korea's nuclear program. He insisted that the government had not helped the North Korean nuclear program in any way. "No material, no technology ever has been exported to North Korea," Qazi said in an interview in 2002. "I can assure you there is no way we would underestimate the seriousness of such an international breach." Qazi said that although Pakistan has engaged in trade with North Korea, "nobody can tell us if there is evidence, no one is challenging our word. There is no smoking gun."

A.Q. Khan, the architect of Pakistan's nuclear program, later confessed to running a global enterprise that supplied nuclear technology and parts to North Korea, Libya and Iran.

The senior State Department official said the United States is not concerned about Qazi's position on the sensitive topic. "It hasn't escaped our notice, but we assume he was just reading the talking points he was given," the official said.

In speeches across the United States, Qazi has been outspoken in promoting peace talks with India, stability in Afghanistan and fighting Islamic extremists in Pakistan and worldwide.

Staff writer Glenn Kessler contributed to this report.

Ashraf Jehangir Qazi is ambassador to U.S.