Nuclear talks in Vienna
Nuclear talks in ViennaReuters

A senior US official said on Thursday that the window is still open to revive the 2015 Iran nuclear deal but won't be forever.

"We're still interested. We still want to come back to the table," the senior State Department official said in a telephone briefing, as quoted by Reuters. "The window of opportunity is open. It won't be open forever if Iran takes a different course."

The official added that Iran has yet to name a negotiator, set a date for talks or say whether it would resume where they left off in June.

The official stressed that the US is prepared to be patient, but said at some point Iran's nuclear advances would overtake the deal and the United States and its partners would have to decide whether Iran was willing to revive it.

Iran has gradually scaled back its compliance with the 2015 deal in response to former US President Donald Trump’s withdrawal from the agreement in May of 2018.

The previous government, headed by former President Hassan Rouhani, had been holding indirect talks with the US on a return to the agreement.

The negotiations were adjourned on June 20, two days after Ebrahim Raisi won Iran's presidential election, and no date has been set for a resumption of dialogue.

US Special Envoy for Iran Robert Malley said recently that Washington "can't wait forever" for Tehran to decide whether it wants to restart the talks.

In response, Iran said the United States is the one that withdrew from the deal, violated the resolution, and threatened those seeking to implement the agreement with punishment.

Tehran signaled on Tuesday that negotiations would resume in a few weeks without giving a specific date.

The US official declined to say what the United States might do if Iran refuses to return to negotiations, or if a resumption of the original deal proves impossible.