The US has promised the "asphyxiation" of the Islamic Republic as it imposed harsh new sanctions on Iran and threatened those who traded with it.

US Treasury Secretary Scott Bessent on Monday said they were working towards the "asphyxiation of this regime" amid the standoff in the Strait of Hormuz.

"Iran now faces a very clear choice, with only two paths before them: complete global isolation and a subsistence economy, or a path back to normalcy with an opportunity to rejoin the global economy," Bessent told reporters in Washington.

Bessant said that "Operation Economic Outcast" would "foreclose" every other option available to Iran, having earlier described the sanctions as an "economic D-Day".

"America is no longer managing the Iranian threat. We are ending it."