US State Department says most of the punitive measures against Iran is imposed on its Revolutionary Guard, putting them among the most heavily sanctioned entities in the world.

The department's spokesman, Ned Price, told a briefing on Tuesday that out of the 107 sanctions the Biden administration has imposed on Iran, 86 – some three-quarters – have been applied against the IRGC or its proxies.

He added that “there are various authorities we can use when it comes to the IRGC... In addition to the FTO, there are a number of other authorities that are used to constrain and constrict its activities and those of its leadership and its proxies as well”.

“The fact is that we do have a number of tools, but whether it’s the SST (State Sponsor of Terrorism), whether it’s the FTO (Foreign Terrorist Organizations) designation, both of these things are defined by statute”, Price said in response to a question about their efficacy, adding that “we are going to follow the law. We’re going to do what’s in our national security interest when it comes to every authority under the sun”.

Talks to revive Iran's 2015 nuclear deal with world powers have stalled since March, chiefly over Tehran's insistence that Washington remove the FTO designation of the IRGC, which is the only example of a sovereign state’s armed forces to be included.