(CNN) -- The United States will not bargain with al Qaeda over the life of an American worker filmed making an emotional plea to President Barack Obama to save his life, U.S. officials said Monday. 

"We don't make concessions to terrorists," State Department spokesman Mark Toner said when asked whether the United States would meet the demands contained in a video posted Sunday to several Islamist websites featuring Warren Weinstein. 

"My life is in your hands, Mr. President," said the American captured in August from his home in the Pakistani city of Lahore. "If you accept the demands, I live. If you don't accept the demands, then I die." 

White House spokesman Jay Carney reiterated the point, saying that while the administration's hearts go out to Weinstein and his family, "we cannot and will not negotiate with al Qaeda." 

Ayman al-Zawahiri, leader of the al Qaeda terror network, listed eight demands that he said, if met, would result in Weinstein's release. The demands related to issues in the Middle East, Pakistan, Afghanistan and Somalia. 

"It is important that you accept these demands and act quickly and don't delay," Weinstein said in the video posted Sunday. 

Toner said that U.S. officials had not corroborated the video and could not say with certainty that the man in the video is Weinstein. 

He said he believes Weinstein is likely being held in the tribal areas of Pakistan, but that the United States has no way to verify it. 

The State Department said Monday that U.S. officials, including the FBI, are assisting Pakistani authorities in the investigation. 
when did the state department divulge that?
Monday