The United States and European powers have voiced disappointment at what they said was Iran's lack of seriousness in the latest round of negotiations on reviving a landmark 2015 nuclear deal.
The talks between Iran and the remaining parties to the nuclear agreement -- Britain, France, and Germany (known as E3), China, and Russia -- resumed on November 29 in Vienna after a five-month hiatus, with the United States participating indirectly.
The White House said Tehran did not bring any 'constructive proposals' to the renewed negotiations that were suspended in Vienna on December 3.
U.S. Secretary of State Antony Blinken said separately on the same day that the talks ended because Iran right now does not seem to be serious about doing what is necessary to return to compliance with the deal.
Earlier, senior E3 diplomats in a statement expressed 'disappointment and concern' at the results of the five days of negotiations in Vienna.
Diplomats were aiming to revive the Joint Comprehensive Plan of Action (JCPOA) which began unravelling in 2018 when former U.S. President Donald Trump pulled out of the deal and reimposed sanctions, prompting Iran to exceed limits on its nuclear program the following year.
Trump's successor, Joe Biden, said the United States was ready to rejoin the JCPOA provided that Iran resumes observing the deal's conditions.
The diplomats from the E3 issued a statement that described their 'disappointment and concern after thoroughly and carefully analyzing Iranian proposed changes to the text negotiated during the previous six rounds,' which started in April and were interrupted in June, when Iran elected a hard-line president.
'Major changes (have been) demanded (by Iran),' the officials said in a statement on December 3, adding that some were incompatible with the 2015 deal.
'Tehran is walking back almost all of the difficult compromises crafted after many months of hard work,' they added.
The E3 diplomats went on to say it was 'unclear how these new gaps can be closed in a realistic timeframe.'
The diplomats said the delegations needed to 'return to capitals to assess the situation and seek instructions, before reconvening next week to see whether gaps can be closed or not'.
'Our governments remain fully committed to a diplomatic way forward. But time is running out,' they said.
White House Press Secretary Jen Psaki told a briefing on December 3 that 'the new Iranian administration did not come to Vienna with constructive proposals.'
Blinken, speaking at a conference in Washington, said the United States would not allow Iran to procrastinate during the process while continuing to advance its nuclear program, warning that Washington will pursue other options if diplomacy fails.
'What we've seen in the last couple of days is that Iran right now does not seem to be serious about doing what's necessary to return to compliance, which is why we ended this round of talks in Vienna,' Blinken said.
'We're going to be consulting very closely and carefully with all of our partners in the process itself...and we will see if Iran has any interest in engaging seriously,' he said.
Iran's top negotiator sounded a defiant note in response to Western criticism, saying European sides can propose their own drafts for discussion, Iranian state media reported.
'There is no problem if the Europeans also provide drafts, and they can be discussed, but they must be based on principles approved by both sides,' Ali Bagheri Kani said, according to the state broadcaster IRIB, before leaving Vienna.
The European Union official chairing the meeting, Enrique Mora, said on December 3 that the talks will start again next week.
"We have identified the challenges ahead. Now it is time to consult with capitals," Mora told reporters. "We will be resuming here in Vienna next week."
Iran's semiofficial ISNA news agency said the talks would 'most likely' resume on December 6, but French President Emmanuel Macron warned that there could be a longer break in the talks.
With reporting by Reuters, AP, and AFP
Copyright (c) 2018. RFE/RL, Inc. Republished with the permission of Radio Free Europe/Radio Liberty, Washington DC 20036