Speaking at a rally in Ohio on Monday, Trump claimed that nobody wanted to become Iran's president, raising questions about who Washington could engage with as diplomatic talks appear to have stalled.

"They got no leaders even. That's why probably we might have gone too far with the leaders, because we don't know who the hell we're dealing with anymore. Nobody wants to be the president of Iran . They have phone calls. Who would like to be the president? Nobody. I don't want it," he claimed.

Trump suggested that the extent of US actions against Iranian leaders had made further diplomatic engagement difficult.

"We're having a hard time figuring out who the hell to deal with, to be honest with you. I think we went too far Bernie, could have stopped at level one; level two and a half was probably going too far," he added.

His remarks come as negotiations between Washington and Tehran appear to have stalled despite earlier diplomatic efforts.

Both countries signed a Memorandum of Understanding in June, but disagreements have continued.

Last month, Trump rejected an Iranian proposal to reopen the strategically important Strait of Hormuz within seven days.

The US president has also ruled out further attacks ahead of the US midterm elections.