Israel-Iranian missile exchanges prompt Trump to call for immediate negotiations "before it's too late," revealing divisions among Republicans and Democrats on Middle East policy

President Donald Trump vetoed a plan presented to the U.S. in recent days to kill Iranian supreme leader Ayatollah Ali Khamenei, according to a U.S. official familiar with the matter.

The president had opposed Israeli action against Iran but came to believe that Israel had reason to act and that the U.S. would have to lend some support.

After canceling negotiations with the U.S. scheduled for Sunday, Tehran has signaled it is willing to talk.

President Donald Trump said Iran was "foolish" not to sign a deal, which he said would have avoided the ongoing conflict with Israel. (Credit: Reuters)

Israeli forces stepped up bombing of Iranian cities, while Iran pierced Israeli air defences with a successful volleys of retaliatory missile strikes.

Tehran has asked Qatar, Saudi Arabia and Oman to press U.S. President Donald Trump to use his influence on Israel to agree to an immediate ceasefire with Iran in return for Tehran's flexibility in nuclear negotiations,