Iran leader rejects Trump's call for surrender; Trump says patience has run out

Iranian Supreme Leader Ayatollah Ali Khamenei rejected Donald Trump's demand for unconditional surrender on Wednesday, and the U.S. president said his patience had run out, though he gave no clue as to what his next step would be.

Speaking to reporters, Trump declined to say whether he had made any decision on whether to join Israel's bombing campaign against the Islamic Republic. The Iranians had reached out but "it's very late to be talking", he said.

"There's a big difference between now and a week ago," Trump told reporters outside the White House. "Nobody knows what I'm going to do."

Iranians jammed the highways out of the capital Tehran fleeing from intensified Israeli airstrikes.

In the latest bombing, Israel said its air force destroyed the headquarters of Iran's internal security service.

"As we promised – we will continue to strike at symbols of governance and hit the Ayatollah regime wherever it may be," Defence Minister Israel Katz said.

Khamenei, 86, rebuked Trump in a recorded speech played on television, his first appearance since Friday.

The Americans "should know that any U.S. military intervention will undoubtedly be accompanied by irreparable damage," he said. "Intelligent people who know Iran, the Iranian nation and its history will never speak to this nation in threatening language because the Iranian nation will not surrender."

Trump has veered from proposing a swift diplomatic end to the war to suggesting the United States might join it. In social media posts on Tuesday he mused about killing Khamenei, then demanded Iran's "UNCONDITIONAL SURRENDER!"

A source familiar with internal discussions said Trump and his team were considering options that included joining Israel in strikes against Iranian nuclear sites.

Israel's military said 50 Israeli jets struck around 20 targets in Tehran overnight, including sites producing raw materials, components and manufacturing systems for missiles. The military told Iranians to leave parts of the capital for their own safety while it struck targets.