The U.S. has evidence that suggests Pakistan assisted North Korea's covert nuclear weapons program as recently as three months ago, much later than previously disclosed.

In the past five years, Iran has used a web of phony trading companies to obscure an increasingly sophisticated drive to secretly build large facilities that could produce the materials needed for nuclear weapons, according to U.S. government officials and information obtained by an Iranian opposition group.

President Bush made an overt appeal to North Korea yesterday, offering to consider agriculture and energy aid to the desperately poor country if it dismantles its nuclear weapons programs.

The United States is preparing to significantly raise its estimate of the number of nuclear weapons held by North Korea, from "possibly two" to at least eight, according to U.S. officials involved in the preparation of the report.

North Korea is likely to be producing nuclear bombs even as it conducts negotiations with the United States and four other countries on ending its weapons programs, the senior U.S. official responsible for those talks told Congress.

U.S. officials are increasingly concerned that North Korea may be preparing its first test of a nuclear weapon, though they warn that the information is sketchy and not definitive.

The U.S. Senate has approved a historic agreement that opens up nuclear trade with India for the first time since New Delhi conducted a nuclear test three decades ago, giving the Bush administration a significant foreign policy achievement in its final months.