Updated

The American turncoat caught fighting with the Taliban says terrorists are planning two more attacks on America: an imminent attack using biological weapons and another attack that will destroy the country, the Washington Times reported.

But U.S. officials don't know if his statements are credible, because of his relatively low-level position in the Al Qaeda terrorist organization.

The Times cites intelligence sources who said John Walker told American officials that the next attack on the United States will take place within days — and will involve biological weapons.

According to the Times, Walker revealed under questioning that "phase two" of Al Qaeda's war against America will happen at the end of the Muslim holy month of Ramadan, which occurs Sunday.

The 20-year-old Californian who converted to radical Islam also reportedly stated that a "phase three" is planned that will result in the destruction of the entire country.

Walker is being held by Marines at their Camp Rhino base in southern Afghanistan. He was captured after holing up with Taliban fighters following a bloody prison uprising.

The Marines are believed to be holding Walker in a large green metal shipping container at Camp Rhino. U.S. officials have said Walker has been providing information, but they wouldn't detail what he's been saying.

"He's been pretty close to the action, and he has provided from the Afghan perspective some useful information," Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff, said on Fox News Sunday.

The Pentagon has not decided whether Walker will be charged with treason.