Trump signs executive order imposing fresh 'hard hitting' sanctions on Iran

US President Donald Trump on Monday signed an executive order, which he said, will impose "hard-hitting" sanctions on Iran and deny the Iranian Supreme Leader and other officials access to financial instruments within US jurisdiction.

Trump's move to impose a fresh set of sanctions on Iran's supreme leader Ayatollah Ali Khamenei and a string of military commanders comes days after Tehran said it shot down an American drone in the region on Thursday.

President Trump called off a planned retaliatory military strike Friday, saying the response would not have been "proportionate".

"We do not seek conflict with Iran or any other country," Trump said in a brief interaction with reporters at his Oval Office here.

"I can only tell you we cannot ever let Iran have a nuclear weapon," he said.

Trump said that the executive order signed by him will impose "hard hitting" sanction on Iran and it will deny the Iranian Supreme Leader and other officials access to financial instruments.

He signed the order in presence of Treasury Secretary Steven Mnuchin.

"I think a lot of restraint has been shown by us but that doesn't mean we're going to show it in the future," Trump said.

"We will continue to increase pressure on Tehran. Never can Iran have a nuclear weapon," he said.

When asked if his executive order was in response to the Iranian attack on US drone, Trump replied "you could probably add that into this" but then said, "this was something that was going to happen anyway."