Donald Trump, the leading Republican contender for U.S. president, says he would return to strong interrogation techniques such as waterboarding if he were elected because their severity pales against Islamic State practices.

"You know, they don't use waterboarding over there; they use chopping off people's heads," Trump said Sunday on ABC's "This Week with George Stephanopoulos." Waterboarding, a method of torture in which water is poured over the face of an immobilized prisoner to simulate drowning, is "peanuts" compared with that, Trump said. He said he "would absolutely bring back interrogation and strong interrogation."

Ben Carson, running 4 percentage points behind Trump in the latest Bloomberg Politics national poll, taken Nov. 15-17, declined to say whether he'd favor waterboarding, during an appearance on the same program.