Donald Trump has said that if he returns to the White House China would not dare provoke him because President Xi Jinping knows the Republican is “crazy”.

Speaking to the Wall Street Journal’s editorial board, Trump said that if elected president next month, he would impose tariffs on China if it sought to blockade Taiwan.

“I would say: if you go into Taiwan, I’m sorry to do this, I’m going to tax you at 150% to 200%,” he said.

On the campaign trail, the Republican candidate has argued that America’s adversaries would not act against US interests under a new Trump presidency because they would fear a forceful, even unpredictable, response.

He told the Wall Street Journal’s editorial board he would not have to use military force to prevent a blockade of Taiwan, because President Xi “respects me and he knows I’m [expletive] crazy”.

“I had a very strong relationship with him,” Trump said of President Xi. “He was actually a really good, I don’t want to say friend – I don’t want to act foolish, ‘he was my friend’ – but I got along with him great.”

“He’s a very fierce person,” Trump added.

The former president also cast his relationship with Russian President Vladimir Putin in a positive light, saying: “I got along with him great.”

But Trump – who has previously been criticised for praising the Russian leader – said he had threatened him not to invade Ukraine.

He told the Journal that he said to Putin: “’I’m going to hit you right in the middle of fricking Moscow.’ I said, ‘We’re friends. I don’t want to do it, but I have no choice.’ He goes, ‘No way.’ I said, ‘Way.’

“I said, ‘You’re going to be hit so hard, and I’m going to take those [expletive] domes right off your head.’ Because, you know, he lives under the domes.”

With his vows to wage trade wars and end US involvement in the Russia-Ukraine war, Trump has branded his foreign policy America First, though detractors say it is isolationist.

The Republican’s choice of JD Vance as his running mate alarmed Ukraine’s allies, as the Ohio senator staunchly opposes sending any more US aid to the country.