The Republican nominee told Reuters that defeating the Islamic State was more important than persuading Bashar al-Assad, the Syrian president, to step down.
“What we should do is focus on Isis. We should not be focusing on Syria,” he said. “You’re going to end up in World War Three over Syria if we listen to Hillary Clinton,” he said.
“You’re not fighting Syria any more, you’re fighting Syria, Russia and Iran, all right? Russia is a nuclear country, but a country where the nukes work as opposed to other countries that talk,” he said.
“Assad is secondary, to me, to ISIS.”
He also said that his Democratic opponent would not be able to negotiate with Vladimir Putin, the Russian president, after demonising him.
“How she is going to go back and negotiate with this man who she has made to be so evil,” if she wins the presidency, he said.
On another day of combative campaigning in Florida, the Republican nominee also promised to repeal and replace Obamacare as soon as he is elected.
“It’s killing our businesses. It’s killing our small businesses. And it’s killing individuals,” he said at a rally in Tallahassee.
Repeating his Brexit theme he said: “There’s gonna be a lot of Brexit happening in about two weeks.”
He also mocked Joe Biden after the vice president had said he wished he could take Trump “behind the gym” to settle things following the revelation of the video tape that showed the Republican being sexually aggressive towards women.
“Mr Tough Guy!” Mr Trump teased. “You know when he’s Mr Tough Guy? When he’s standing behind a microphone by himself!”
Mrs Clinton, who was also campaigning in Florida, a key swing state, warned her supporters against complacency despite her massive lead in almost all opinion polls.
“I hope you will come out and vote because it’s going to be a close election. Pay no attention to the polls. Don’t forget, don’t get complacent, because we’ve got to turn people out,” she said.