Republican presidential candidate Donald Trump after speaking at a caucus night watch party | Ethan Miller/Getty Images Trump on nuclear button: ‘I would be very, very slow on the draw’ ‘I know what I’m doing. I’m a smart person,’ the Republican frontrunner said.

The real Donald Trump would be cautious with the nuclear button as commander-in-chief.

In an interview with People magazine carrying the headline “Who Is the Real Donald Trump? ‘I’m a Much Nicer Person than People Would Think,’” the Republican front-runner said using nuclear-launch codes would be his final option.

“That would be such a last resort,” Trump said, according to early excerpts of the cover story provided to POLITICO Playbook. “Nobody is going to mess with us. But I would very, very slow on the draw.”

Trump has relentlessly attacked his opponents, nicknaming rival Ted Cruz as “Lyin’ Ted” and even bringing the Texas senator’s wife to the fore by threatening to “spill the beans” and retweeting an unflattering image of her beside a glamorous shot of his wife, Melania.

“I’m a much nicer person than people would think, to see me from the outside,” he told the magazine in an interview conducted March 18. “On the one hand you might see that as bad. But on the other hand you don't want people to know you that well.”

But despite his sometimes controversial off-the-cuff comments, the real-estate mogul maintained that he knows what he’s doing, as evidenced by his victories in the GOP primaries.

“I know what I'm doing. I'm a smart person. The highest level of smart,” he boasted.