The official declined to provide specifics about what the Iranians had proposed, however added, “based mostly on their reply, we look like shifting backwards.”

A European diplomat agreed with this destructive evaluation and mentioned that the Iranian response appeared “destructive and never affordable.” One other particular person conversant in the state of affairs merely added that the Iranian reply did “not look good in any respect.”

It’s not clear how for much longer the assorted events concerned can be prepared to maintain negotiating, although neither Iran nor the U.S. is prone to completely rule out diplomacy. The Biden administration official didn’t reply to questions on whether or not the U.S. would stroll away from the talks given the most recent Iranian response.

The politics of the nuclear talks are delicate in each Iran, the place hardliners have been ascendant within the Islamist regime that guidelines the nation, in addition to the U.S. Earlier Thursday, for example, a bipartisan group of U.S. lawmakers despatched a letter to President Joe Biden elevating issues about points of the negotiations.

A deal to revive the 2015 settlement will probably face a evaluation in Congress. However with midterm elections developing in November, many Democrats specifically might need to keep away from an Iran debate within the weeks instantly prior.

“With this chance squandered, it’s now onerous to think about {that a} deal can occur earlier than the midterms,” mentioned Ali Vaez, a high analyst with the Worldwide Disaster Group.

With midterm elections developing within the U.S., it’s doable that talks may stall till after these races are completed in November.

Iranian officers couldn’t instantly be reached for remark Thursday night.

The 2015 nuclear deal lifted a slew of U.S. and different sanctions on Iran in alternate for extreme curbs on its nuclear program. In 2018, then-President Donald Trump deserted the settlement, saying it was too weak. He reimposed the sanctions, and within the years since, Iran has resumed a lot of its nuclear program.

Biden has sought to re-enter the settlement, however the negotiations — which have been mediated largely by European officers — have been fraught and prolonged.

Earlier this summer season, European officers introduced what they known as a “closing textual content” of a roadmap to revive the 2015 settlement. However Iran has raised issues about components of it, and the U.S. has made its personal counter options.

In an earlier response to the U.S., Iran raised factors associated to financial ensures. Iran is frightened, amongst different issues, that even when a deal is revived, international corporations will nonetheless think about it too dangerous to take a position there, particularly if it’s doable {that a} future Republican U.S. president will as soon as once more stroll away from the settlement.

Washington and Tehran have additionally tangled on different issues, equivalent to Biden’s unwillingness to take away Iran’s Islamic Revolutionary Guard Corps from a terrorist blacklist.

Iran additionally has had issues a few separate investigation of the Worldwide Atomic Vitality Company, the U.N. nuclear watchdog, into traces of nuclear materials discovered at sure Iranian websites.

This week, Iran has additionally expanded using superior IR-6 centrifuges to its underground nuclear website in Natanz, in line with an IAEA report seen by Reuters, having beforehand already used them on the above-ground plant in Natanz in addition to at its website in Fordow.

The IR-6 centrifuges are highly effective machines that may enrich uranium to increased ranges a lot sooner than the extra fundamental IR-1 centrifuges. Beneath the unique 2015 nuclear deal, Iran is simply allowed to make use of the essential IR-1 centrifuges.

A daily assembly of the Board of Governors of the IAEA is because of start in Vienna on Sept. 12. The 35-member physique will think about the latest developments of Iran’s nuclear program amongst different issues.

Stephanie Liechtenstein reported from Vienna, Austria.