Washington: The United States has welcomed Pakistan's investigation of reports that Pakistani scientists have transferred nuclear technology to Iran.

"We made clear our view that all nations should avoid nuclear cooperation with Iran, particularly in the areas of weapons development; that Iran needs to comply with all the requirements of the Board of Governors," State Department spokesman Richard Boucher said.

"So we've welcomed the inquiry or investigation that the Pakistanis are conducting into reports of possible ties from the past," he added.

"We think that's a positive process and demonstrates once again a Pakistani intention to carry out President Musharraf's commitment that he made to us that Pakistan will not be involved in any sort of transfers involved in weapons of mass destruction," Boucher said.

Meanwhile, Deputy Secretary of State Richard Armitage told National Public Television that US believed Musharraf's pledge not to proliferate nuclear weapons.

Asked what Pakistan should do with the scientists now identified as the possible source of nuclear proliferation in Iran, Libya and North Korea, Armitage said, "We've had good discussions with the Government of Pakistan about this. They are in the process of interviewing and interrogating at least three nuclear scientists."

"I saw a statement from Pakistan today where the Government said they may have been motivated by personal ambition and greed. So if that's the case and they were evading the laws of Pakistan, I hope the Pakistanis will wrap them up, and I think they will," he added.

Asked if US was supporting Musharraf at the cost of possibly turning a blind eye to nuclear proliferation, Armitage said, "No, that would really be against our long-term interest."

"President Musharraf has pledged that there won't be these transfers. In the last two years that I've been working closely with him, we have not seen such transfers, and I believe him."