The Trump administration is striking back against Iran for several tanker attacks and last week's downing of a US drone in the Strait of Hormuz with sanctions meant to cut off the nation's financial resources.

The US Department of the Treasury's Office of Foreign Assets Control (OFAC) placed the "hard-hitting" measures against leaders of Iran's Islamic Revolutionary Guards Corp (IRGC) being held responsible for the allegedly unprovoked attacks.

"The United States is targeting those responsible for effectuating the Iranian regime's destructive influence in the Middle East," treasury secretary Steven Mnuchin said in a statement today.

"IRGC commanders are responsible for the Iranian regime's provocative attacks orchestrated in internationally recognised waters and airspace, as well as Iran's malign activities in Syria."

Frontline's 110,000-dwt Front Altair (built 2016) and Japanese-owned 27,000-dwt Kokuka Courageous (built 2010) on 13 June were attacked in the S in an incident the US quickly blamed on Iran.

A month earlier, four other tankers were assailed in a "sabatoge attack" off the coast of Fujairah.

"This action is a warning to officials at all levels of the IRGC and the rest of the Iranian regime that we will continue to sanction those who export violence, sabotage, and terrorism,” Mnuchin said.

The sanctions name eight IRGC leaders, including commander Ali Reza Tangsiri.

"As recently as February 2019, Tangsiri threatened that the Iranian regime's forces would close the Strait of Hormuz ... if US sanctions stopped stopped Iran's oil exports, and that the Iranian regime is prepared to target US interests in the region," OFAC said in a statement.