WASHINGTON — Vice President Cheney said this week that dunking terrorist suspects in water during questioning was a “no-brainer,” prompting complaints from human-rights advocates that he was endorsing the use of a technique known as waterboarding on prisoners held by America.

In an interview Tuesday with Scott Hennen, a conservative radio show host from Fargo, N.D., Mr. Cheney agreed with Mr. Hennen’s assertion that “a dunk in water” may yield valuable intelligence from terrorism suspects. He also referred to information gleaned from Khalid Sheikh Mohammed, the alleged architect of the September 11, 2001, attacks, but stopped short of explicitly saying what techniques were used.

“Would you agree a dunk in water is a no-brainer if it can save lives?” Mr. Hennen asked.

“Well, it’s a no-brainer for me,” Mr. Cheney said. “But for a while there, I was criticized as being the vice president for torture. We don’t torture. That’s not what we’re involved in.”

Mr. Cheney said the technique has been a “very important tool” used against high-level Al Qaeda detainees such as Khalid Sheikh Mohammed, and that they do not, in his view, constitute torture. The comments underscore continuing uncertainty over precisely which techniques can be used legally during CIA interrogations of terrorism suspects. Senator McCain, a Republican of Arizona, and other lawmakers have said recent legislation that established ground rules for interrogations should effectively bar waterboarding and other methods that are viewed as violations of the Geneva Conventions and American criminal law. But Bush administration officials have repeatedly declined to say which techniques they believe are permitted under the new law or to discuss methods used in the past.

Numerous sources have said the CIA subjected Mr. Mohammed and other “high-value” terrorism suspects to waterboarding, a technique that gives the prisoner the sensation of drowning. A Cheney spokeswoman said yesterday that Mr. Cheney was not confirming the use of any specific interrogation techniques.

“He was talking about the interrogation program without torture,” a spokeswoman, Lee Anne McBride, said. “The vice president does not discuss any techniques or methods that may or may not have been used in questioning.”

Congress passed legislation last month putting limits on interrogation techniques that could be used on prisoners declared to be “unlawful enemy combatants,” but largely left it to the executive branch to decide whether many techniques would be legal.