The United States and European Union voiced frustration at the UN this week over the slow pace with Iran, saying its new government showed no indication it was ready to revive a nuclear accord.
Iran's new ultraconservative president, Ebrahim Raisi, strongly denounced the United States in a video address to the General Assembly Tuesday and indicated he backed a return to indirect talks with the United States in Vienna, although he did not give a timeline.
"We don't have yet an agreement by Iran to return to the talks in Vienna," Secretary of State Antony Blinken told reporters Thursday before leaving the annual UN summit.
"We're pretty much prepared to return to Vienna to continue the talks. And the question is whether -- and if so when -- Iran is prepared to do that," Blinken said.
"We await an answer on that."
The talks, brokered by the Europeans, seek the return of the United States to the agreement trashed by former president Donald Trump -- as well as Iran's return to full compliance.
European nations said they heard nothing concrete as they met with Iran's new foreign minister, Hossein Amir-Abdollahian, who came to New York.
Trump's successor Joe Biden again said in his own address he wants to return to the accord, under which Iran drastically scaled back nuclear work. Since the United States left the deal in 2018, Iran retreated from many of its commitments.
The months of talks in Vienna made little concrete progress and the process went into a standstill in June, with Iran saying it needed time after the transition from a more moderate government of Hassan Rouhani.
Another US official said that nothing transpired in New York to make the Biden administration more optimistic.
"For now, certainly there's no indication, positive indication, that Iran is prepared to come back," he said on condition of anonymity.
"The window of opportunity is open and won't be open forever,"
Blinken again said that Iran's nuclear work will eventually make it pointless to revive the accord, although he stopped short of giving a timeframe.
- 'Clock is ticking' -
Foreign Minister Heiko Maas of Germany, one of five nations that negotiated with Iran and remains in the accord, warned that patience was thinning.
"The clock is ticking. We're not going to wait two or three months for the Iranian delegation to come back to the table in Vienna," Maas told reporters.
"It has to happen more quickly," he said.
EU foreign policy chief Josep Borrell said that Amir-Abdollahian told him that Iran was ready to restart talks "at an early date" but gave no more precise time.
Similarly, Iran's foreign ministry said only that nuclear talks would resume "in the coming weeks."
The delay has drawn particular suspicion in Israel, which sees Iran's clerical leadership as an existential threat and has waged a sabotage campaign.
Barbara Slavin, an expert on Iran at the Atlantic Council, said that Tehran ultimately had an interest in returning to talks for the sake of the relief of sanctions which have taken a heavy economic toll.
"They're taking their sweet time," Slavin said.
"I still think they have to come back to the talks. I think they need it," she added.