The Bush administration is planning three-way talks with Britain and Libya (search) to set the stage for sending U.S. and British analysts to Libya to check on the extent of Tripoli's nuclear weapons program and its promise to dismantle it.

A series of meetings with British officials, which began last week with a trip to London by Under Secretary of State John R. Bolton, will culminate with top-level Libyans joining the conversation after additional U.S.-British meetings.

Then U.S. and British analysts will go to Libya, working on a parallel track with the International Atomic Energy Agency (search), whose estimate of the Libyan program is considered understated by some senior Bush administration officials.

U.S. intelligence has uncovered an elaborate network of technology assistance to Libya, including the shipment of thousands of pieces of equipment for processing enriched uranium.

A shipment was intercepted in early October and diverted to Italy. There may have been other interceptions under a program initiated last May, but senior U.S. officials declined to provide any details on grounds any such information was secret.

The seizure sealed Libyan leader Muammar al-Qaddafi's (search) decision Dec. 19 to dismantle his nuclear weapons program, a U.S. official said last week on condition of anonymity.

Britain, which took the lead in pressuring Libya to end the program, has invited the Libyan foreign minister, Abdelrahman Shalqam, to London. Foreign Secretary Jack Straw (search) said Monday the reason was to discuss "the process of implementing the decision by Libya to dismantle its weapons program."

Whether Pakistan President Pervez Musharraf (search) could have been unaware of the proliferation of sensitive technology is unclear. A senior U.S. official, in disclosing forthcoming talks with top-level Libyans, declined to say whether Musharraf knew about any transfers by Pakistani nuclear scientists.

But Secretary of State Colin Powell said he had talked to Musharraf about proliferation several times and found no reluctance to look into the problem.

"To the extent we can help him with information we will," Powell told reporters.

The government of Pakistan on Tuesday vehemently denied it had helped Libya acquire centrifuge technology critical to producing nuclear weapons.

Gen. Musharraf's support for the U.S. campaign to counter the al Qaeda terror network and to stop Pakistani extremists from crossing into the Indian-held portion of Kashmir is considered vital.

"This is a story still unfolding," White House press secretary Scott McClellan said Tuesday in fending off questions about sales of equipment to Libya.

McClellan said Musharraf had assured President Bush he would try to restrain Pakistani scientists. "We fully expect President Musharraf and the government of Pakistan to follow through on those assurances," the White House official said.

At the same time, though, McClellan said it was difficult to control "rogue individuals."

Bush has called for a U.N. resolution urging all nations to pass legislation to prohibit and punish such transfers, "and we are going to continue working tirelessly with our friends around the world in that effort," McClellan said.

There is an extensive black market that provided Libya with tens of millions of dollars in equipment, another senior U.S. official said last week. But this official said there was now an aggressive program of interdicting delivery, and the administration intends to pursue middlemen actively.