Secretary of State Hillary Rodham Clinton on Wednesday warned of dire consequences from the spread of nuclear weapons, while a special U.S. panel asserted that the more worrisome and urgent threat is terrorists attacking the United States or its allies with biological weapons.

In a speech outlining the Obama administration's nuclear arms agenda, Clinton cited a range of troubling trends abroad, including a failure to stop North Korea from developing a nuclear bomb and weakness in the United Nations agency that is responsible for monitoring nuclear programs worldwide.

"Unless these trends are reversed _ and reversed soon _ we will find ourselves in a world with a steadily growing number of nuclear-armed states and an increasing likelihood of terrorists getting their hands on nuclear weapons," Clinton said.

Separately, a panel created by Congress, the Commission on the Prevention of Weapons of Mass Destruction Proliferation and Terrorism, said the U.S. was making better progress in regard to the nuclear threat than it was preparing for possible bioterrorism.

"The nation's level of preparedness for dealing with the threat of bioterrorism remains far lower than that of the nuclear threat," the commission said in a lengthy report titled "The Clock Is Ticking."

It said the government needs to move more aggressively to address the threat of bioterrorism, and that the threat is misunderstood by many.

"Unlike nuclear weapons, which require highly advanced technology, massive infrastructure, and rare materials that can be closely monitored and secured, biological weapons materials occur naturally, require no significant infrastructure to produce and can be found in nearly every part of the world," the commission said.

"As technology advances, the ability to prevent biological attacks diminishes."

The commission lauded the White House's National Security Council for creating a bioweapons prevention strategy, which the panel said was the first of its kind. But it said the NSC needs a senior official whose sole responsibility is to improve the country's capability to defend against a bioweapons attack.

"The near-term biodefense goal of the United States should be to limit the consequences of a bioweapons attack," the panel said. "The long-term goal should be to improve post-attack capabilities for rapid recognition, response and recovery to a level that bioterrorism would no longer be considered a weapon of mass destruction."

The commission did not discount the significance of the nuclear threat, while calling it less urgent.

"The current trends, if left unchecked, will increase the odds that al-Qaida will successfully develop and use a biological weapon or a nuclear device against the United States or its allies," it said.

Atop Clinton's list of key challenges in the spread of nuclear weapons technology was North Korea, which has an active nuclear weapons program in defiance of U.N. Security Council resolutions.

"The international community failed to prevent North Korea from developing nuclear weapons," she said. Continued...