Iran being able to enrich enough uranium to produce a nuclear bomb could be a "matter of weeks," U.S. State Secretary Antony Blinken told NBC in an interview published Monday.
The estimate was for the scenario where Tehran continues rolling back its commitments under the 2015 nuclear deal -- something it has gradually been doing since the US pullout in 2018.
Otherwise, Iran could still develop the capacity to enrich enough uranium for a warhead within months, Blinken said.
The diplomat stressed that Washington was willing to return to the agreement if Iran was to reverse its breaches.
He also urged Iran to work with the United States and other nations on an accord that would last longer and encompass more issues and points of contention.
When pressured on the fates of Americans being held prisoner by Tehran, Blinken did not bind them to the reinstatement of the US compliance to the accord, instead saying the prisoners must be freed "irrespective" of any agreements.
In his first interview for the media after being confirmed by the Senate, Blinken also condemned the Russian arrests of demonstrators supporting jailed Kremlin critic Alexei Navalny, while also rejecting Moscow's claims that the US was behind the recent protests.
He also chided China over a lack of transparency and cooperation with the World Health Organization team of experts, currently in the country attempting to find the origins of the coronavirus pandemic that has blighted large swathes of the world for the last 12 months.