Donald Trump stood by his support for what he called “enhanced interrogation techniques” Monday, writing that he’s willing to do “whatever it takes to protect and defend this nation.”

The billionaire businessman defended his call for such practices, in an op-ed for USA Today, responding to critics who say such techniques — including waterboarding — are torture and aren’t effective at getting valuable information from terror suspects.

“Though the effectiveness of many of these methods may be in dispute, nothing should be taken off the table when American lives are at stake,” Trump wrote. “The enemy is cutting off the heads of Christians and drowning them in cages, and yet we are too politically correct to respond in kind.”

And Trump, who is the Republican presidential front-runner, argued that his position demonstrated strong executive leadership.

“The people of the United States expect their president to make such decisions, and I will not disappoint them. I will do whatever it takes to defend this nation and its people,” he said, adding, “I cannot imagine knowing that something could have been done to save American lives, and then not taking those actions.”

Trump’s opinion as an outspoken advocate for harsh interrogation techniques has been a common occurrence on the campaign trail, most notably when he vigorously defended water boarding at a recent debate.

“I’d bring back waterboarding,” Trump said during a February 7 debate. “And I’d bring back a hell of a lot worse than waterboarding.”

Torture is banned in the United States, which is defined by federal statute as “an act committed by a person acting under the color of law specifically intended to inflict severe physical or mental pain or suffering (other than pain or suffering incidental to lawful sanctions) upon another person within his custody or physical control.”

The definition further elaborates that “‘severe mental pain or suffering” means the prolonged mental harm caused by or resulting from “a variety of factors,” including “the threat of imminent death.”

It is also banned by a U.N. convention ratified by the U.S.