VIENNA -- EU, Iranian and Russian diplomats sounded upbeat as Iran and world powers held their first talks in five months on Monday to try to save their 2015 nuclear deal, despite Tehran taking a tough stance in public that Western powers said would not work.
Diplomats say time is running out to resurrect the pact, which then-U.S. President Donald Trump abandoned in 2018, angering Iran and dismaying the other powers involved -- Britain, China, France, Germany and Russia.
European Union, Iranian and Russian delegates to the talks offered an optimistic assessment after the new round began with a session of the remaining parties to the deal, without the United States -- whom Iran refuses to meet face-to-face.
"I feel extremely positive about what I have seen today," Enrique Mora, the EU official chairing the talks, said after the meeting - the seventh round of talks aimed at reviving a deal under which Iran limited its disputed uranium enrichment program in return for relief from U.S., EU and U.N. economic sanctions.
Mora told reporters the new Iranian delegation had stuck to its demand that all sanctions be lifted. But he also suggested Tehran had not rejected outright the results of the previous six rounds of talks held between April and June.
"They have accepted that the work done over the first six rounds is a good basis to build our work ahead," he said. "We will be of course incorporating the new political sensibilities of the new Iranian administration."
The meeting in Vienna ended a long hiatus triggered by the election in June of Ebrahim Raisi, an anti-Western hardliner. The talks are effectively indirect negotiations between Tehran and Washington, with other officials shuttling between them.
Tehran's negotiating team has set out demands that U.S. and European diplomats consider unrealistic, Western diplomats say.
Iran has adopted an uncompromising position by demanding the removal of all U.S. and European Union sanctions imposed since 2017, including those unrelated to its nuclear program, in a verifiable process.
The Islamic Republic's top negotiator Ali Bagheri Kani also said the United States and its Western allies should offer guarantees that no new sanctions would be imposed in the future.
“It is a major achievement that all parties in the meeting accepted Iran’s demand that first the situation of illegal and unjust U.S. sanctions...should be cleared and then (we) discuss other issues and decide on those issues,” he told reporters.
There was no immediate comment from the big powers on Bagheri Kani's remarks about the sequencing of topics.
In parallel, Tehran's conflicts with the U.N. atomic watchdog, which monitors its nuclear program, have festered.
As Iran has advanced its uranium enrichment, the International Atomic Energy Agency says its inspectors have been treated roughly and refused access to reinstall monitoring cameras at a site it deems essential to reviving the deal.
"If Iran thinks it can use this time to build more leverage and then come back and say they want something better, it simply won't work. We and our partners won't go for it," U.S. envoy Robert Malley told BBC Sounds on Saturday.
Since Trump took the United States out of the deal, Iran has breached many of its restrictions meant to lengthen the time it would need to generate enough fissile material for a nuclear bomb. Iran says it wants to enrich uranium only for civil uses.
Malley said Washington would be ready to ramp up pressure on Tehran if the talks collapse.
Diplomats have said Washington has suggested negotiating an open-ended interim accord with Tehran as long as a permanent deal is not achieved. Several Iranian officials told Reuters Iran had no intention of accepting an interim deal.
Iran's arch-enemy Israel, which opposed the original deal as too limited in scope and duration, has said military options will be on the table if diplomacy fails.