As the trial for five men believed to be behind the Sept. 11 terrorist attacks began over the weekend, al Qaeda was sending fresh threats to the United States in an online message.
The new video released by al Qaeda shows American hostage Warren Weinstein in Pakistan, pleading for his life.
The former aid worker was kidnapped last year, and his forced plea to President Obama is the latest reminder that al Qaeda is still a threat.
Al Qaeda staged the event with Weinstein, 70, seated behind a platter of food.
"My life is in your hands, Mr. President," he said. "If you accept the demands, I live. If you don't accept the demands, then I die. It's important that you accept the demands and act quickly and don't delay."
This is the first time Weinstein has been seen since eight armed terrorists captured him from his home in Lahore, Pakistan, in August 2011.
"I've done a lot of service for my country, and I would hope that my country will now look after me and take care of me and meet the demands of the mujahedeen," Weinstein said.
He doesn't mention what al Qaeda's demands are in the video. But on a website last year, a group called for an end to all U.S. air strikes in Afghanistan and the release of al Qaeda members around the world.
Meanwhile, a military trial is underway for self-proclaimed 9/11 mastermind Khalid Sheik Mohammed and four others at the U.S. base in Guantanamo, Cuba.
On Saturday, the inmates disrupted the trial by refusing to answer questions, spontaneously praying, and shouting that guards would kill them.
Family members of 9/11 victims, who traveled to Guantanamo Bay and East Coast military bases to watch the trial on closed circuit TV, were upset.
"The fiasco, the circus that's taking place at Guantanamo, it just emphasizes that they don't need to have a platform," 9/11 widower Tom Heidenberger said.
"I've only seen body language and that in itself indicates that they have nothing but contempt for our values and our way of life, and it would upset anybody to see this demonstration," 9/11 widow Maureen Basnicki added.
While officials work to verify that the Weinstein tape is authentic, al Qaeda's battle in the military courtroom is expected to go on for months, if not years.