The United States said on Thursday it had little cause for optimism about reviving the 2015 Iran nuclear deal and would know in a day or so if Iran would negotiate in good faith as Tehran put forward fresh proposals.
"I think, in the very near future, the next day or so, we'll be in a position to judge whether Iran actually intends now to engage in good faith," US Secretary of State Antony Blinken told reporters in Stockholm.
"I have to tell you, recent moves, recent rhetoric, don't give us a lot of cause for ... optimism. But even though the hour is getting very late, it is not too late for Iran to reverse course and engage meaningfully," he added.
Iran has provided European powers who are shuttling between US and Iranian officials with drafts on sanctions removal and nuclear commitments, Iran's top nuclear negotiator said on Thursday, as world powers and Tehran try to reinstate the pact.
The announcement came on the fourth day of indirect talks in Vienna between Iran and the United States on bringing both fully back into the deal, under which Iran limited its nuclear program in return for relief from US, European Union and UN economic sanctions.
The talks resumed on Monday after a five-month hiatus prompted by Iran's election of an anti-Western hardliner as president.
