Donald Trump says not currently mulling American ground troops in Iran

President Donald Trump said Thursday it would be a "waste of time" currently to consider sending US ground troops into Iran, NBC News reported, dismissing the Iranian foreign minister's warning that such a move would spell disaster for invaders.

"It's a waste of time. They've lost everything. They've lost their navy. They've lost everything they can lose," he told NBC by telephone, adding that Foreign Minister Abbas Araghchi's earlier remark that Iran was ready for a US or Israeli ground invasion was a "wasted comment."

Trump also indicated he is keen to see Iran's leadership structure removed and that "we want to go in and clean out everything" quickly.

"We don't want someone who would rebuild over a 10-year period," he said. He added that he had ideas for a new leader but declined to name anyone.

Trump said earlier he would "have to be involved" in the appointment of Iran's next leader after US-Israeli strikes killed Ayatollah Ali Khamenei when the conflict began on Saturday.

Heavy attacks were reported in Tehran on Friday after Israel said it was hitting "regime infrastructure" in a "new phase" of the war it launched with the US against Iran.