The new US sanctions targeting Iran's supreme leader and other top officials mean the "permanent closure" of diplomacy between Tehran and Washington, Iran's Foreign Ministry spokesman has said.

That is according to a report carried by the state-run IRNA news agency on Tuesday, quoting spokesman Abbas Mousavi.

Mr Mousavi says the "fruitless sanction on Iran's leadership and the chief of Iranian diplomacy mean the permanent closure of the road of diplomacy with the frustrated US administration".

US president Donald Trump enacted new sanctions on Monday targeting Iran's Supreme Leader Ayatollah Ali Khamenei.

READ MORE: Gulf on brink after oil tanker blasts

US officials also say they are planning sanctions against Iranian Foreign Minister Mohammad Javad Zarif.

Washington says the measures were taken to discourage Tehran from developing nuclear weapons and supporting militant groups.

They came amid heightened tensions between Iran and the US over Tehran's unravelling nuclear deal with world powers.

The Herald:

Burning tanker in Gulf of Oman

Mr Mousavi's statement echoed that of Iran's UN ambassador, Majid Takht Ravanchi, who warned on Monday that the situation in the Persian Gulf was "very dangerous" and that any talks with the US were impossible in the face of escalating sanctions and intimidation.

Meanwhile, the US envoy at the United Nations, Jonathan Cohen, said the Trump administration's aim was to get Tehran back to negotiations.

The sanctions follow Iran's downing last week of a US surveillance drone, worth over 100 million US dollars (£78.4 million), over the Strait of Hormuz, an attack that sharply escalated the crisis in the Persian Gulf.

After the downing of the drone, Mr Trump pulled back from the brink of retaliatory military strikes but continued his pressure campaign against Iran.

Mr Trump last year re-imposed sanction on Iran after pulling the US out of the nuclear pact that world powers made with Tehran in 2015.

The Herald: Iran's Supreme Leader Ayatollah Ali Khamenei

Ayatollah Ali Khamenei

Other nations stayed in the deal, which eased sanctions on Iran in exchange for curbing its nuclear programme.

The latest round of sanctions denies Mr Khamenei and senior Iranian military figures access to financial resources and blocks their access to any financial assets they have under US jurisdiction.

Mr Trump said the new sanctions were not only in response to the downing of the American drone.

READ MORE: UK envoy's bid to ease tension between Iran and US stumbles

The US has blamed Iran for attacks on two oil tankers this month near the Strait of Hormuz. Citing those episodes and intelligence about other Iranian threats, the US has sent an aircraft carrier to the Persian Gulf region and deployed additional troops alongside the tens of thousands already there.

The sanctions were announced as US Secretary of State Mike Pompeo was holding talks in the Middle East with officials in the United Arab Emirates and Saudi Arabia about building a broad, global coalition that includes Asian and European countries to counter Iran.

Mr Pompeo is likely to face a tough sell in Europe and Asia, particularly from those nations still committed to the 2015 nuclear deal.