Al Qaeda leader Usama bin Laden threatened in a new audio recording released Thursday to kill any captured Americans if the U.S. executes the accused mastermind of the Sept.11 attacks or any other Al Qaeda suspects. The U.S. is still considering whether to put Khalid Sheik Mohammed and four of his fellow plotters on military tribunal for their role in the Sept. 11 attacks. The Obama administration is also looking into recommendations for civilian trials, and is expected to announce a decision soon.

In a brief 74-second audio tape aired on Al-Jazeera television, bin Laden said if the U.S. decides to execute any Al Qaeda suspects in its custody -- and explicitly mentioned Mohammed -- his terror network would kill American captives.

The terror leader said such a decision "would mean the U.S. has issued a death sentence against whoever of you becomes a prisoner in our hands."

U.S. politicians have "oppressed us and still do, especially by backing Israel, which occupies the land of Palestine," the Al Qaeda chief said.