Osama bin Laden is threatening to kill any American captured by al-Qaida if the United States executes the alleged mastermind of the September 11, 2001 terrorist attacks.
The Arabic television network al Jazeera aired an audiotape on Thursday, in which bin Laden explicitly mentions Khalid Sheikh Mohammed, who is set to be tried in a U.S. federal court or military tribunal.
Mohammed and four alleged co-conspirators could face the death penalty for charges that include murder and terrorism in connection with the 2001 attacks on the U.S.
In the audio message, bin Laden also said U.S. President Barack Obama is following in the footsteps of his predecessor, George W. Bush, by escalating the war in Afghanistan, oppressing al-Qaida prisoners, and supporting Israel in its "occupation of Palestinian land."
There was no immediate independent verification of the recording's authenticity.
White House spokesman Robert Gibbs did not respond directly to the comments Thursday, but said the Obama administration will keep up the pressure to destroy the al-Qaida network.
The U.S.-based IntelCenter that monitors terrorist propaganda, said bin Laden's threat could signal an increased kidnapping risk targeting Americans during the trial of Khalid Sheikh Mohammed in the U.S.
Some information for this report was provided by AFP, AP and Reuters.