The intelligence community does not yet believe Iran is moving toward a nuclear weapon, according to Director of National Intelligence Tulsi Gabbard.

The U.S. on Tuesday imposed sanctions on entities and individuals in Iran, the United Arab Emirates and China whom it accused of being part of an Iranian weapons procurement network, as President Donald Trump seeks to ramp up pressure on Tehran.

Iran and Russia took decisively different approaches in response to President Donald Trump's threats as Tehran vowed action against any "mischief" while the Kremlin remains tight-lipped.

The United States issued fresh Iran-related sanctions on Tuesday targeting six entities and two individuals based in Iran, China and the United Arab Emirates, the Treasury Department said on its website.

Iran's Supreme Leader Ayatollah Ali Khamenei said on Monday the U.S. would receive a strong blow if it acts on Trump's threat to bomb unless Tehran reaches a new nuclear deal.

Iran's Revolutionary Guards have seized two overseas-registered tankers in the Persian Gulf accused of fuel smuggling.

U.S. President Donald Trump said this week that if Iran did not strike a deal with the United States over its nuclear programme "there will be bombing", adding to U.S. ally Israel's long-standing threat to attack Iran's nuclear facilities.