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Muammar al-Qaddafi (search), the Libyan leader who had spent years defying the international community, seemed eager to scrap his weapons programs during months of secret meetings, U.S. officials said Saturday.

Prior to Friday's surprise announcement, officers from the Central Intelligence Agency (search) and British Intelligence held talks with al-Qaddafi in Libya's capital in the dead of night.

The negotiations led to Libya's decision to end work on its programs to develop nuclear, chemical and biological weapons, including an effort to refine uranium for use in nuclear devices, the officials said.

Al-Qaddafi's son said Saturday his father made his decision after receiving assurances that the United States was not plotting against him. Libya also claimed it had acted on its own to serve as an inspiration for the rest of the world.

In recent years, al-Qaddafi has tried to improve relations with the West. He initiated the weapons talks and the following onsite inspections in March after he agreed to admit to complicity in the 1988 bombing of a Pan Am airliner over Lockerbie (search), Scotland.

Al-Qaddafi made the overture for the weapons talks just days before the U.S.-led invasion of Iraq.

The United States and Britain said Libya's decision was a significant step forward in the effort to keep such weapons from ending up in the hands of a terrorist organization or hostile country.

President Bush said the downfall of Saddam Hussein (search) and U.S. efforts to crack down on North Korea's pursuit of weapons helped influence al-Qaddafi's decision, said President Bush.

Senior intelligence officials, including one on the inspection team that went to Libya, talked to reporters Saturday about the events leading up to Libya's announcement. They spoke on condition they not be identified.

Most significant among the discoveries was that Libya had built a working centrifuge for uranium enrichment. To make weapons-grade uranium, a raw form of the substance can be passed through a series of centrifuges that slowly create a product capable of nuclear fission.

Such programs need hundreds of centrifuges, called a cascade, to make significant quantities of uranium over a reasonable time. The inspection teams saw only one or a few centrifuges, and the Libyans denied that any enriched uranium had been produced.

The intelligence officials refused to say how Libya obtained centrifuge technology. Both Iran and North Korea are thought to have the technology, as are a number of companies and U.S. allies.

Before their meetings with al-Qaddafi, the American and British intelligence officers were whisked around Tripoli, the capital, by Libyan security officials, sometimes changing cars before arriving at the sites of meetings with al-Qaddafi.

Al-Qaddafi was described as agreeable, laying out proposals for disarming and allowing inspections. He provided information about Libyan weapons programs that Western intelligence agencies had been unaware of.

The Libyans had chemical weapons and medium-range missiles from North Korea and, at a minimum, a program to make uranium for nuclear weapons. U.S. intelligence agencies lack information that Libya had enriched the uranium to make a nuclear weapon or possessed biological weapons. For all the Libyan cooperation, officials acknowledged there still could be undisclosed weapons and programs.

So far, the United States has learned that Libya had:

— Tens of tons of mustard agent, a World War I-era chemical weapon, produced about 10 years ago.

— Aircraft bombs capable of dispersing the mustard agent in combat.

— A supply of Scud-C ballistic missiles made in North Korea. The weapons can hit targets 500 miles away.

Much of this information reinforced the CIA's assumptions, intelligence officials said, although some expressed surprise at how far the Libyans' nuclear program had advanced.

Early in the year, before contacts began, Libyan officials approached the British government to open discussions. Washington was later included in negotiations that took place at an undisclosed location in Europe.

After some initial visits to Tripoli, a team of CIA and British intelligence personnel went to Libya in October to inspect weapons sites. The team included technical experts on weapons programs.

At some point, the CIA presented the Libyans with its intelligence about the programs. The Libyans were surprised at how much the agency knew, the officials said, then provided much more information.

The second inspection visit, in December, was more fruitful, the officials said.

During the visits, the team went to 10 sites related to Libya's nuclear effort, chemical stockpile and missile program.

The U.S. intelligence officials also acknowledged that authorities had stopped a shipment intended to supply Libya's weapons program. They would provide no details.

It is unclear if the intelligence team will return, the officials said. Libya has agreed to allow U.N. inspectors access to its programs.

Al-Qaddafi also agreed to get rid of missiles with ranges longer than 186 miles, which would include the North Korean Scud-Cs but not Scud-Bs, which have the 186-mile range.

The officials said Libya was developing the weapons for its defense, but they refused to discuss whether Libya had provided weapons or expertise to other countries.

Bush said that if Libya shows it is serious in honoring its commitment, there was the possibility of U.S. help in making Libya "a more free and prosperous country."

The United States has a 17-year embargo in place against Libya and continues to list Libya among nations that sponsor terrorism. Britain's foreign secretary indicated that Washington may lift the embargo.

The Associated Press contributed to this report.