Donald Trump Says Hillary Clinton 'Doesn't Know How to Win'

Donald Trump fired back at Hillary Clinton a day after she accused the Republican nominee of being too thin-skinned to be under control of the country's nuclear arsenal -- saying she "doesn't know how to win."

In a combative Democratic National Convention speech in which Clinton name-checked her Republican opponent 22 times, she said of Trump, "A man you can bait with a tweet is not a man we can trust with nuclear weapons."

Trump defended himself in an interview with ABC News' George Stephanopoulos and blasted Clinton as dishonest and weak.

"I think I have a great temperament, I have a temperament where I know how to win," Trump said. "She doesn't know how to win, she's not a winner. She doesn't know how to win. And this country, if they choose her, this country will not be in good shape."

He also accused Clinton of being dishonest about his abilities as a campaigner.

"I've had a beautiful, I've had a flawless campaign," he said. "You'll be writing books about this campaign."

Trump also said divisions still linger within the Democratic Party even after a convention that saw Clinton and her primary contender Sen. Bernie Sanders attempt to unify their supporters.

"If you look at what's going on in terms of unity, the Bernie people are angry. They're angry. He was angry," Trump said. "What was amazing to me is when she was talking about Bernie last night, the camera was on him and he was angry. It almost looks like he has buyer's remorse, like he shouldn't have made the deal."

See more of Trump's interview Sunday on "This Week."