U.S. Secretary of State Antony Blinken on Friday said that the latest round of Iran nuclear talks ended because Iran right now does not seem to be serious about doing what is necessary to return to compliance with a 2015 deal.

Blinken, speaking at the Reuters Next conference, said that the United States would not let Iran drag out the process while continuing to advance its program and that Washington will pursue other options if diplomacy fails.

"What we've seen in the last couple of days is that Iran right now does not seem to be serious about doing what's necessary to return to compliance, which is why we ended this round of talks in Vienna," Blinken said. 

"We're going to be consulting very closely and carefully with all of our partners in the process itself ... and we will see if Iran has any interest in engaging seriously," he said.

Indirect U.S.-Iranian talks on saving the nuclear deal broke off until next week as European officials voiced dismay on Friday at the demands of Iran's new, hardline administration.

The 2015 agreement put restrictions on Iran's nuclear programme in exchange for the easing of some international sanctions. In 2018 then-President Donald Trump pulled the United States out of the deal, calling it too soft on Tehran, and reimposed painful U.S. economic sanctions on Tehran. Iran then began breaching many of the deal's limits on enrichment and other restrictions.

 "If the path to a return to compliance with the agreement turns out to be a dead-end, we will pursue other options," Blinken said, but declined to spell out what those would be.

Reuters