US President Donald Trump said on Monday that Iran had “tapped everyone along" for nearly five decades, but that “very friendly negotiations" are currently taking place between Washington and Tehran.

Speaking at a rally in Michigan, Trump said Iran has been bullying the Middle East and the United States and repeated his criticism of former President Barack Obama for sending Iran $1.7 billion in cash as part of the 2015 nuclear deal.

“You can't bribe them. You gotta beat them. And we are beating the hell out of them. We’ll see how it turns out," Trump added.

“The fuel came down for a little while. Then [Iran] didn't behave, and I had to go back. Now they are behaving again," he continued.

“When somebody comes up and says, ‘Why are we doing this?’ just say, ‘Because we cannot let Iran have a nuclear weapon.’ It's very simple. It's all you have to say. There is nothing else you have to say," Trump stated.

Earlier, Trump spoke to reporters aboard Air Force One and said Iran had requested negotiations after suffering heavy damage from US military action.

“They want to meet, and we're meeting. We'll see what happens. There's a chance we can make a deal," said the President, who added that Iran’s request for talks resulted from US pressure.

“Without what we did, they wouldn't even be talking to us," he said. “They requested a meeting through their surrogates and directly and we're meeting."

Asked about his patience with Iran, Trump replied: “I have plenty of time. The whole shoreline is wiped out. The Strait is in very good shape. And we're talking right now."

“We're having good talks, so we'll see what happens. I think there's a good chance something could happen. And if it doesn't, we go back to doing what we were doing two days ago."

On the weekend it was reported that Trump put off a major escalation of the military campaign against Iran amid efforts to revive diplomacy to open the Strait of Hormuz and a debate over the impact of declining munitions stocks.

Trump denied that dwindling munitions are a problem, telling The Wall Street Journal in a statement that “we have far more munitions than anyone in the world, and far more than we need."