Russia's Deputy Foreign Minister Sergei Ryabkov said that there was reason to expect some progress on the restoration of a 2015 nuclear deal with Iran, and that the chances of reaching an agreement had increased.

After the recent exchanges in the stop-start negotiations, talks to revive the nuclear pact have resumed in Vienna, with both parties seeking to gauge the chances of success.

Iran said on Sunday that European countries had failed to make constructive recommendations to help revive a 2015 nuclear agreement, after Britain suggested there was still time for Tehran to rescue it but that this was the last chance.

Russian deputy foreign minister meets with Venezuelan leader in Caracas - Committee on International Affairs

"European parties have failed to come up with any measures to resolve differences on the easing of sanctions on Iran." He said, referring to the UK, France, and Germany, who are among the major powers attempting to save the deal.

"This is the last chance for Iran to come to the negotiating table with a serious resolution to this issue, which needs to be agreeing the terms of the JCPOA (nuclear deal)," British Foreign Secretary Liz Truss said earlier on Sunday.

"This is their last chance, and they must seize it. Iran will not be allowed to have a nuclear weapon," Truss said.

On Saturday, Germany warned that time was running out to find a way to revive a 2015 nuclear deal.