Iran will abandon a landmark deal to stop the country from developing nuclear weapons unless it receives guarantees that the economic incentives of the pact will be protected by the other parties, a senior Iranian official has warned.
The news follows the US decision to unilaterally withdraw, and Washington's threat of sanctions against companies who trade with Iran.
"We are still complying but we have not decided whether to stay in the deal or not," the official told reporters on condition of anonymity.
"It depends on the remaining JCPOA [Joint Comprehensive Plan of Action] participants, if they can actually compensate for the absence of the United States in the deal."
The other countries involved in the JCPOA met on Friday for the first time without the US after Iran called for an urgent meeting of the body in Vienna.
Britain, France, Germany, China and Russia reaffirmed their commitment to the deal, and the Iranian delegation emerged saying they were more confident than before, and made no mention of timelines.
Britain, France, Germany, China and Russia reaffirmed their commitment to the deal, and the Iranian delegation emerged saying they were more confident than before
"I think we have good reasons to think we will succeed, provided that, once again, all of us have relevant political will," said Mikhail Ulyanov, head of the Russian Foreign Ministry's arms control and non-proliferation department.
The other nations have all previously said they want to stay in the 2015 deal, which limits Iran's enrichment and stockpiling of material that could be applied to a nuclear weapons programme.
In exchange, Tehran was granted widespread relief from international trade, oil and banking sanctions.
Speaking ahead of the Vienna talks, the Iranian official said that for his country to stay in the deal, the relief granted would have to be guaranteed by the other parties involved and that Tehran needs specifics on how that will happen by the end of May. Tehran will make its final decision in a "few weeks".
The official said that in theory the deal can survive without the US, but acknowledged "in practice I'm not sure".
He acknowledged the timeline was tight, but said that European nations had "wasted" the past few months trying to convince President Donald Trump not to pull out of the nuclear deal over his contention it was not tough enough on Iran.
Among other things, Mr Trump said the deal needed to address Iran's ballistic missile programme and involvement in regional conflicts while the others had argued those issues could be negotiated separately.
New US sanctions are being phased in, but already many non-US companies have said that they are likely to curtail operations in Iran for fear of losing access to the much more important American market.
Iran is looking for guarantees it can continue to sell its oil on world markets, have international banking access and broad protection for ongoing trade, among other things.
"We cannot continue the deal... unless the remaining participants will compensate and take countermeasures against US sanctions and continue economic relations with Iran," the official said.