Updated

Recently obtained videotapes of Al Qaeda terrorists in training "don't advance the ball on anything at all," U.S. officials told Fox News Monday.

"This is interesting, but nothing we didn't already know," officials said after videotapes surfaced that show Al Qaeda in Afghanistan demonstrating bomb-making and poison gas experiments.

U.S. officials said the intelligence community has long known about Al Qaeda's desire to get their hands on chemical and biological weapons -- and from what they've seen so far, it doesn't appear these tapes provide anything new on that front.

They further doubt that they'll be able to get any "actionable intelligence from them," meaning they don't expect that the tapes will lead them to any new suspects.

But officials said that CNN, which obtained the tapes, had not given them access to the videos yet, and that the Pentagon would like to see them in their entirety.

The videotapes, which were taken out of Afghanistan, show dogs dying agonizing deaths after being introduced to poison gas, as well as Al Qaeda operatives practicing ambushes and kidnapping. Most of the tapes appear to have been made before Sept. 11, although some show television coverage of the attacks in New York and Washington.

The network said it showed the tapes to several experts to verify their authenticity.

A CNN spokeswoman, Christa Robinson, declined to say more about how the tapes were obtained. She said the network did not believe they were being used in any way by Usama bin Laden's organization to get a message across.

Gordon Johndroe, spokesman for the White House's Office of Homeland Security, said the tapes "are consistent with our previous information that [Al Qaeda leaders] would use chemical weapons if they're able to obtain them." He said there was still no credible information that the group had been successful in its effort to obtain weapons of mass destruction.

"This is just further evidence of why it's necessary to continue to prosecute this war on terrorism -- both overseas and here at home," Johndroe said.

The New York Times, which was shown portions of the tapes last week, quoted an expert who viewed the tapes as saying they suggest Western intelligence agencies may be underestimating Al Qaeda.

In conjunction with Al Qaeda's written manuals, "the tapes show meticulous planning, preparation and attention to the tradecraft of terror," said Marcus Ranstorp, director-designate of the Center for the Study of Terrorism and Political Violence at the University of St. Andrews in Scotland.

There have been previous indications in Al Qaeda materials that the terror group was interested in chemical weapons. Last year, The Associated Press obtained an 11-volume "Manual of Afghan Jihad" prepared for Al Qaeda operatives.

The manual included instructions on plants that can be used to make poison gas, how to make the gas, and what quantity is needed to kill a man. It also described how a room full of a particular odorless gas will kill someone in 30 seconds.

Fox News' Bret Baier and the Associated Press contributed to this report.