Russia’s envoy in Vienna has tweeted Wednesday that despite difference between Iran and the United States, “it is feasible” to reach a nuclear agreement.

“Our contacts with the US and Iran at #ViennaTalks prove that both sides are very serious about restoration of $JCPOA but their visions of relevant ways and means differ,” Mikhail Ulyanov wrote.

The European Union’s coordinator of the talks to revive the Iran nuclear deal (JCPOA), Enrique Mora, announced Wednesday that negotiations will resume in Vienna on Thursday.

Last week, Russia, China, the United Kingdom, France and Germany held talks Iran’s representatives for five days that ended on Friday with any results, generating pessimism.

President Joe Biden and Russian President Vladimir Putin discussed Iran during their videoconference on Tuesday.

Iran has hardened its position since the election of hardline president Ebrahim Raisi. Western diplomats say that Tehran has reneged on compromises reached in earlier rounds of talks from April to June.

Iran is demanding that all post-2018 sanctions to be lifted at once before it agrees to return to JCPOA. Tehran is enriching uranium to as high as 60 percent, violating the agreement.