The United States says it wants more information about the nuclear black-market activities of detained Pakistani scientist Abdul Qadeer Khan. Secretary of State Condoleezza Rice discussed the proliferation issue with Pakistani leaders as part of wide-ranging discussion.

Secretary of State Rice says she told Pakistani President Pervez Musharraf and other top leaders that Washington is committed to completely eliminate any remnants of the A.Q. Khan nuclear black market.

"We all have an interest in knowing what happened, that we all have an interest in making sure that this network does not continue to operate in any way. And perhaps most importantly, we all have an interest in knowing how it happened, so we can safeguard against this kind of black market entrepreneurship in the future," she said.

Described as the father of Pakistan's atomic bomb, Mr. Khan has confessed to illegally selling nuclear technology to several foreign countries, including Iran.

The Pakistani scientist is currently under house arrest and is being question by authorities, but few details of the interrogation have been made public.

For the first time last week, senior Pakistani official admitted Mr. Khan gave Iran centrifuges, which could be used for making fuel for nuclear weapons.

Ms. Rice said the Khan network represent a threat to the entire world, and said everything possible must be done to uproot any illegal nuclear proliferation.

"It is a network that we want to make certain that its tentacles are broken up as well, and so we have cooperation with other countries on that front," she added.

Among other issues, Ms. Rice discussed democratic reforms by the Musharraf administration.

Pakistani opposition parties say that the president's reforms are undemocratic and he is setting himself up as a military dictator.

Pervez Musharraf

Ms. Rice praised President Musharraf for making progress to democratize Pakistan following his 1999 coup. But she says she also discussed concerns about Pakistan's democracy, including a parliamentary election in 2007.

"We will always talk about the need for democracy," she said. "It is central to our dialogue with every country in the world, and it is also central to our dialogue here."

Secretary Rice also voiced support for Pakistan's ongoing peace dialogue to resolve bilateral disputes with neighboring India.

She admitted that many problems remain, including the contested territory of Kashmir.

"But they can be overcome in an atmosphere of goodwill, an atmosphere of commitment to better relations between India and Pakistan, then I'm quite certain that all issues can eventually be resolved," she said.

Ms. Rice was in Pakistan as part of a tour Asia, including stops in China, South Korea, India, and Afghanistan.