U.S. officials say the captured American who fought with the Taleban in Afghanistan has described plans for a bio-terror attack on the United States in the next few days. But the officials are largely dismissing the information.

U.S. military and intelligence officials have been questioning 20-year-old John Walker since his capture in northern Afghanistan last month for clues about al-Qaida and Osama bin Laden, who continues to elude capture.

On Sunday, Joint Chiefs of Staff Chairman General Richard Myers told Fox News the American has in fact, been cooperating. "He's been pretty close to the action and I think he has provided at least from the Afghan viewpoint, some useful information and will probably continue to do so," he said.

U.S. intelligence officials who asked not to be identified say Mr. Walker has told his interrogators of an al-Qaida plan to use a biological weapon to launch an attack on the United States that would coincide with the end of the Muslim holy month of Ramadan.

But U.S. officials are casting doubt on whatever he may have said regarding possible plans for another al-Qaida attack, largely because the captured American was only a Taleban foot soldier, and not part of the al-Qaida hierarchy. "It is hard to imagine how somebody who is in a position that he was, how somebody in that position could obtain information that was credible or reliable about a future action," said White House spokesman Ari Fleischer. "As you know, clearly in the case of the September 11th attacks, that information was extraordinarily limited in the number of people that Al-Qaida or Osama bin Laden informed about ahead of time."

Still, Attorney General John Ashcroft suspects the bin Laden network may be planning more attacks in the United States. "We live in a time where terrorists are active and there has been every indication from Osama bin Laden that he has instructed his terrorist followers to remain active," he said.

And this new threat relayed to the United States by the captured American in Afghanistan comes just a week after Homeland Security Director Tom Ridge issued another nationwide alert, warning Americans of an increased threat of terrorism, especially, he said around the end of Ramadan which occurs Sunday.