An audiotape purportedly from al-Qaida leader Osama bin Laden threatens new attacks against the United States.

The tape's authenticity has not been confirmed. It says there are plans for a new attack in the United States, but offers a "long-term" truce if American forces pull out of Iraq and Afghanistan.

The White House flatly rejected the purported offer, with a spokesman saying the United States does not negotiate with terrorists.

The message says heightened security in the United States has not prevented attacks. It says the delay is simply due to preparations for new operations.

Arab broadcaster Al-Jazeera first broadcast selections from the recording earlier Thursday.

There has been no specific information on when the tape was recorded, but the voice makes reference to sinking public opinion polls for President Bush.