Washington DC, Feb. 7 -- US President Donald Trump on Friday signed an executive order reaffirming the national emergency with respect to Iran and establishing a mechanism to impose additional tariffs on countries that continue to do business with Tehran, the White House said.

Under the order, beginning on its effective date, the United States may impose an additional ad valorem duty-for example, up to 25 per cent- on goods imported into the US from any country that directly or indirectly purchases, imports, or otherwise acquires goods or services from Iran. The move is aimed at protecting US national security, foreign policy and economic interests.

The White House said the order establishes a system that allows Washington to levy tarif...