In the wake of a worldwide anthrax scare, the U.S. said on Monday that it has identified six countries trying to make biological weapons — and none of them are friends of America.

It is "beyond dispute" that Iraq has a germ-warfare program, and the U.S. strongly suspects North Korea, Libya, Syria, Iran and Sudan of the same, undersecretary of state for arms control John R. Bolton said Monday, addressing a conference of the 144 nations that have signed the 1972 Biological Weapons Convention.

"The United States strongly suspects that Iraq has taken advantage of three years of no U.N. inspections to improve all phases of its offensive biological weapons program," Bolton said.

Bolton was speaking in Geneva, at the start of a three-week review of the 1972 convention. He was presenting the new U.S. approach to the enforcement of the ban after the anthrax attacks on New York, Washington and Florida.

Iraq's biowarfare program could make it a target in the U.S. war on terror.

"We do not need the events of September 11 to tell us that (Saddam Hussein) is a very dangerous man who is a threat to his own people, a threat to the region and a threat to us because he is determined to acquire weapons of mass destruction," Condoleezza Rice, President Bush's national security adviser, said on Sunday.

Bolton said the United States believes North Korea had a dedicated, national-level effort to achieve a biological weapons capability and that it has "developed and produced, and may have weaponized" biological agents. That thought, he said, is "extremely disturbing."

He also said the United States was "quite concerned" about Iran, Libya, Syria and Sudan.

Ali Asghar Soltanieh, the Iranian ambassador to the conference, said the allegation that his country was developing biological weapons was "unjustified and baseless."

Bolton's comments are all the more frightening because the United States knows "that Usama bin Laden considers obtaining weapons of mass destruction to be a sacred duty" and wants to use them against the United States," Bolton said. 

"We are concerned that he could have been trying to acquire a rudimentary biological weapons capability, possibly with support from a state."

But he said the United States was "not prepared to comment whether rogue states may have assisted" bin Laden in the plan.

In a message to the conference, U.N. Secretary-General Kofi Annan said the U.S. faced a clear challenge in dealing with the threat of biological weapons.

"The horrific attacks on Sept. 11 could have been far worse if weapons of mass destruction had been used," Annan said. "In recent weeks, the world has seen the use of biological agents to create chaos and terror violating the international norm."

Though they agree that biological weapons have to be curtailed or stopped, the conference members are at odds about how to do so.

The United States has rejected a legally binding inspection plan under the biological-weapons treaty, instead preferring a mechanism under which the U.N. secretary-general would order inspections when violations are suspected. American officials shocked other countries last July by rejecting more than six years of negotiations on enforcement measures of the 1972 treaty, arguing they were ineffective.

Other countries said the binding commitment is necessary if the treaty is to be effective.

Belgian Ambassador Jean Lint, speaking for the European Union, said the 15-nation bloc also supports the inclusion of "investigation measures" under the treaty.

Bush demanded that all 144 countries that have signed the treaty enact "strict national criminal legislation" against violations of the treaty and apply strict extradition requirements.

Under the proposed protocol, there would be a limited number of inspections of biotech industries and defense facilities.

The United States said the enforcement proposal would be ineffective in stopping countries from developing biological weapons while it would pose risks to U.S. national security and to commercial secrets of the U.S. biotech industry.

The treaty drafters omitted an enforcement mechanism when they negotiated the accord during the Cold War, in part because no one seriously thought anyone would try to use such weapons.

The Associated Press contributed to this report.