Blinken said that “what we’ve seen in the last weeks and months is an Iran that’s actually moving forward” with its nuclear programme.

The United States unilaterally withdrew in 2018 from the Iran nuclear deal, which was designed to regulate Tehran’s atomic activities in exchange for the lifting of international sanctions.

Speaking at a security forum in Colorado, Blinken blamed the collapse of the nuclear deal for the acceleration in Iran’s capabilities.

“Instead of being at least a year away from having the breakout capacity of producing fissile material for a nuclear weapon, [Iran] is now probably one or two weeks away from doing that,” Blinken said.

He added that Iran had not yet developed a nuclear weapon.

Iran’s acting Foreign Minister Ali Bagheri told CNN earlier this week that his country remained committed to the deal, known as the Joint Comprehensive Programme of Action.