US Special Envoy for Iran Robert Malley said on Sunday that he was not confident that a nuclear deal between world powers and Iran was imminent after 11 months of talks in Vienna that have stalled.
"I can't be confident it is imminent.. a few months ago we thought we were pretty close as well," Malley said at the Doha Forum international conference, Reuters reported.
"The sooner we get back into the deal, which is in our interest, and presumably Iran's interest, the more faithfully we implement it."
His assessment of negotiations in Vienna to revive a 2015 nuclear accord seemed to contradict Kamal Kharrazi, a senior advisor to Iran's Supreme Leader Ayatollah Ali Khamenei.
"Yes, it's imminent. It depends on the political will of the United States," Kharrazi told the conference.
Then-US President Donald Trump abandoned the pact in 2018, prompting Tehran to start violating its nuclear limits about a year later, and months of on-and-off talks to revive it paused in Vienna earlier this month after Russia presented a new obstacle.
Russia later said it had received written guarantees that it would be able to carry out its work as a party to the deal, suggesting Moscow could allow it to be resuscitated.
The failure of efforts to restore the pact could carry the risk of a regional war, or lead to more harsh Western sanctions on Iran and continued upward pressure on world oil prices that are already high due to the Ukraine conflict, analysts say.
Kharrazi said it was vital for Washington to remove the foreign terrorist organization (FTO) designation against Iran's elite Revolutionary Guard Corps (IRGC).
"IRGC is a national army and a national army being listed as a terrorist group certainly is not acceptable," he said.
Tehran has also been pushing for guarantees that any future US president would not withdraw from the deal, which would curb Tehran's nuclear program in exchange for lifting tough sanctions which have hammered Iran's economy.
The extent to which sanctions would be rolled back is another sensitive subject.