The US has singled out Iran’s Revolutionary Guard Corps for tighter sanctions because of its stake in the country’s economy and involvement in missile and nuclear programmes, a senior administration official has said.

Stuart Levey, the under-secretary at the Treasury who has led US measures against Iran’s economy for five years, told the Financial Times there was “growing agreement around the world” that the Revolutionary Guard was an “appropriate target”.

Mr Levey cited its involvement not just in the missile programme but “in the construction of a network of underground tunnels to conceal and protect nuclear and other installations”. He also noted the group’s support for extremist groups internationally, including Hizbollah in ­Lebanon.

But Mr Levey highlighted “favouritism for regime cronies” in Iran. He alleged that the Revolutionary Guard and its subsidiaries benefited from preferential government treatment, including “billions of dollars worth of contracts diverted to them [for] expanding the Tehran metro or managing the airport or road construction for developing oil and gas fields”. Washington is looking for measures against the Revolutionary Guard both at the unilateral level and at the United Nations, where the US hopes to win support for a fresh sanctions resolution against Iran in the next few weeks.