The top U.S. weapons inspector has not returned to Iraq since he came home for a year-end holiday, leading many to expect he is about to step down even as Vice President Dick Cheney says inspectors need more time to look for weapons of mass destruction.

While no final decisions have been announced, David Kay (search) is not expected to return to Baghdad as head of the team of more than 1,000 scientists, translators and other experts searching for banned weapons. Among those being considered to replace him is Charles Duelfer (search), a former U.N. weapons inspector.

Duelfer served from 1993 to 2000 as the deputy executive chairman of the U.N. Special Commission on Iraq. That is the organization charged with eliminating weapons of mass destruction and ensuring that now-deposed Iraqi President Saddam Hussein did not resume production of banned weapons after the 1991 Gulf War.

With that experience, Duelfer has significant connections, including relationships with Iraqis and members of Kay's Iraq Survey Group.

Duelfer did not return calls Thursday to his office at a private think tank in Washington. Kay could not be reached for comment.

Kay's group has been stymied for months in its search for clear evidence of chemical, biological and nuclear weapons in Iraq, one of the Bush administration's main justifications for the invasion.

As recently as last week, CIA Director George Tenet (search) met with Kay, congressional aides said. The two men discussed the strategy for the weapons search and Kay's views on other subjects.

In an interview on National Public Radio, Cheney said he believes Saddam's government had programs to produce weapons of mass destruction, citing a classified interim report from Kay.

"It's going to take some additional considerable period of time in order to look in all of the cubby holes and ammo dumps in Iraq, where you might expect to find something like that," Cheney said in the interview.

A U.S. official, who spoke on condition of anonymity, said Thursday much work remains in Iraq and no time frame has been set for the Iraq Survey Group (search) to finish its job or issue a new interim report.

The United States has spent at least $900 million in the weapons search.

The top Democrat on the Senate Intelligence Committee, Jay Rockefeller of West Virginia, said he is not convinced that the inspectors are on the brink of finding any weapons and he is getting nervous about the expense. But he wants the issue resolved. "I am glad they are continuing to do the search," Rockefeller said.

The Senate Intelligence Committee is holding an inquiry into the accuracy of the prewar intelligence. Rockefeller wants the review expanded to include whether the administration misused intelligence about Saddam's capabilities.

House Intelligence Committee Chairman Porter Goss, R-Fla., said he does not read anything into any possible leadership changes at the study group. In the weapons search, he is encouraging patience and common sense — "two words that no longer apply in an election year," Goss said.

"With the capture of Saddam there is obviously going to be a ton more material to track down, so I suspect we are going to be this for a long, long time, given the warehouses of stuff that still has to be translated," Goss said.

One former Iraq weapons inspector, David Albright, said the Bush administration should begin facing and acknowledging that it was "wrong on many things." Albright said Duelfer's experience as a U.N. inspector would give him credibility in the weapons search.

"We do have to find closure on this," said Albright, who heads the Institute for Science and International Security in Washington.