US President Donald Trump has signaled his clear support for regime change in Iran, calling it "the best thing that could happen."

"They've been talking, talking, talking for 47 years. And we've lost a lot of lives in the meantime," he said on Friday.

While Trump declined to say who he wants to run Iran, he said "there are people" who could take over.

Iran's Supreme Leader Ayatollah Ali Khamenei has not yet responded to Trump's latest comments.

The USS Gerald R. Ford, the world's largest and newest aircraft carrier, is set to move from the Caribbean to the Middle East "soon," Trump said.

Trump shared a photo on his Twitter account of the aircraft carrier moving to join a second US warship in the Middle East.

The Pentagon sent the aircraft carrier to the Middle East in January.

This comes after the United States threatened to attack the Iranian government to stop the killing of thousands of protesters.

Despite threatening to attack Iran if a nuclear deal is not reached between the two countries, Trump stressed that talks with Tehran would continue after meeting with Israeli Prime Minister Benjamin Netanyahu at the White House on Wednesday.