Trump said the sanctions would have been imposed regardless of drone attack Washington has repeatedly imposed sanctions on Tehran since last year WASHINGTON: US President Donald Trump on Monday signed an executive order that would impose fresh sanctions on Iran, amid increased tensions between the long-time foes. Trump initially told reporters the sanctions, which will target Iranian Supreme Leader Ayatollah Ali Khamenei and his office, were in response to Tehran"s downing of a US drone last week. Tehran has said the drone was flying in its airspace, which Washington has denied. Later, Trump said the sanctions would have been imposed regardless of the incident over the drone. The US will also blacklist Iran"s Foreign Minister Mohammad Javad Zarif and block "billions" more in Iranian assets as part of expanded sanctions, US Treasury Secretary Steven Mnuchin said Monday. Mnuchin told reporters Zarif would be added to an economic sanctions list "later this week," adding that eight top military commanders from Iran"s Revolutionary Guards have now also been blacklisted. The US has also blamed Iran for attacks earlier this month on two oil tankers at the entrance of the Gulf of Oman. Iran, in turn, has denied that it is to blame. Washington has repeatedly imposed sanctions on Tehran since last year, when the US withdrew from the 2015 Iran nuclear deal to curb Iran"s nuclear program in exchange for easing of sanctions. Trump’s administration has said the deal struck under his predecessor President Barack Obama did not do enough. Trump has said he would be open to talks with Iranian leaders, but Tehran has rejected such an offer unless Washington drops the sanctions. The Trump administration wants to force Tehran to open talks on its nuclear and missile programmes and its activities in the region. The US also accuses Iran of encouraging allies in Yemen to attack Saudi targets. In a joint statement on Monday, the US, Saudi Arabia, the UAE and UK expressed concern over Middle East tensions and the dangers posed by Iranian "destabilizing activity" to peace and security in Yemen and the region.