President Bush wants to expand international law enforcement efforts to stop the flow of technology and expertise relating to weapons of mass destruction. Mr. Bush used his weekly radio address to repeat his call to limit sales of nuclear enrichment and reprocessing equipment.

As part of the fight against terrorism, President Bush wants a U.N. resolution requiring all countries to enact strict export controls on weapons-related technologies. He is calling for broader international inspections of all nuclear sites and a ban on the sale of nuclear enrichment or reprocessing equipment to any state that does not already have those facilities.

"The Nuclear Non-Proliferation Treaty, one of the most important tools for preventing the spread of nuclear weapons, is undermined by a loophole that allows countries to seek nuclear weapons under the cover of civilian nuclear power programs. I propose that the world's leading nuclear exporters close that loophole," the president said.

The president said the terrorist attacks of September 11, 2001 raised the prospect of what he called the greatest threat before humanity today -- a secret and sudden terrorist attack with weapons of mass destruction.

"Terrorists and terrorist states are in a race for weapons of mass murder, a race they must lose. They are resourceful. We must be more resourceful. They are determined. We must be more determined," he said. "We will never lose focus or resolve. We will be unrelenting in the defense of free nations, and rise to the hard demands of our dangerous time."

The president has agreed to meet privately with a commission he appointed to investigate the September 11 attacks. The commission has suggested the possibility of public testimony from the president at a later time, but a White House statement said there is no need, as Mr. Bush can provide all the information privately.

In his weekly radio address, the president said America is confronting terrorist threats with open eyes and unbending purpose. He says U.S. intelligence agencies are adapting to new and emerging threats.

The president said U.S., and British intelligence officers helped break up the black market operations of Pakistani scientist Abdul Qadeer Khan who has admitted to selling equipment and expertise related to weapons of mass destruction.

Mr. Bush wants the International Atomic Energy Agency to establish a special committee to focus on safeguards and verification. The president says no nation under investigation for proliferation violations should be able to serve on that committee or on the governing board of the U.N. nuclear agency.