After years of denials, Pakistan admitted Thursday that its top nuclear scientist sold crucial equipment to Iran (search), but said it knew nothing of his activities when they occurred and insisted he will not be turned over to another country for prosecution.

The admission by the Pakistani information minister was the first public acknowledgment that Abdul Qadeer Khan (search) provided Iran's secret nuclear program with centrifuges, a crucial component needed to enrich uranium and produce nuclear material for warheads.

"Dr. Abdul Qadeer gave some centrifuges to Iran," the minister, Sheikh Rashid Ahmed, told The Associated Press in a telephone interview. "He helped Iran in his personal capacity, and the Pakistan government had nothing to do with it."

Ahmed initially made the admission at a seminar in Islamabad (search) organized by a local newspaper group, in which he stuck by Pakistan's insistence that Khan would never be handed over to a third country for prosecution. The scientist is considered a hero by his countrymen for nearly single-handedly producing atomic bombs for Pakistan to counter rival India's nuclear arsenal.

"I support the idea that the government should tell the people about these sensitive matters," Ahmed said at the seminar, according to an audiotape obtained by the AP. "I am not a spokesman for a cowardly nation. Yes, we supplied Iran the centrifuge system. Yes, Dr. Qadeer gave Iran this technology. But we are not going to hand over Dr. Qadeer to anyone. We will not."

Ahmed later told the AP that Pakistan's government is fully cooperating with the International Atomic Energy Agency, the U.N. body that is investigating the extent of Khan's illicit sales of nuclear technology to Iran, Libya, North Korea and other countries.

In Mexico City, Secretary of State Condoleezza Rice (search) said she was not surprised by the news, saying Khan "was a very busy and nefarious figure who was transferring technology in almost a turnkey way."

President Bush has urged world leaders to stand united in stopping Iran from obtaining nuclear technology that could be used to produce atomic arms.

Rice, in Mexico to meet with President Vicente Fox and Foreign Secretary Luis Ernesto Derbez, said the United States is moving closer to a decision on incentives for Iran.

The Iranian regime has said it wants to use uranium enrichment for the peaceful purpose of fueling reactors to generate electricity, but the process also can produce material for weapons.

Pakistan is a key ally in the war on international terrorist groups, but American officials acknowledge privately that Washington has been frustrated by Islamabad's refusal to allow Khan to be questioned by American agents.

President Gen. Pervez Musharraf pardoned the scientist last year and allowed him to keep the riches he allegedly earned from his illicit nuclear deals. However, Khan remains restricted to his home in an upscale neighborhood of the Pakistani capital.

Musharraf's government has steadfastly denied any official involvement in the sales, despite reports Khan flew to North Korea on a government plane. Musharraf, a general who seized power in a 1999 coup, held senior positions in the Pakistani military for much of the time that Khan's alleged nuclear dealings took place.

A more than two-year IAEA investigation already has established that Iran ran a clandestine nuclear program, including uranium enrichment, for nearly two decades.

As the main supplier of black market centrifuges, parts and related technology, the Khan network has figured prominently in the IAEA's investigation. Diplomats close to the agency say that in confidential discussions with IAEA experts, the governments of both Pakistan and Iran had acknowledged Khan sold centrifuges to Iran, but neither had said anything publicly until Thursday.

The CIA released a report in November saying it believed Khan provided more help to Iran's nuclear weapons program than previously disclosed, but the unclassified version of the report made no mention of actual centrifuges being delivered to the Iranians.

"The A.Q. Khan network provided Iran with designs for Pakistan's older centrifuges as well as designs for more advanced and efficient models and components," the report said.

Pakistan disputed that account. But in the past it has denied details of Khan's role, only to acknowledge them once evidence came to light.

The IAEA announced Feb. 28 that Iran had revealed it received an "extensive" written offer from the Khan network in 1987 to set up the basics of a uranium enrichment program for Iran.

Diplomats have told the AP that Iran claimed to have refused offers of technology specifically geared toward making weapons.

"They indicated that they did not take these people up on the entirety of the offer," IAEA head Mohamed ElBaradei said. He added, however, that the agency still had to confirm that the Iranians "only got what they told us they got out of this offer."