Nuclear talks in Vienna
Nuclear talks in ViennaReuters

British Foreign Secretary Liz Truss told Iran on Sunday that there was still time to save the 2015 nuclear deal it signed with world powers, but warned that this is the last chance for Iranian negotiators to come to the table with serious proposals.

"This is the last chance for Iran to come to the negotiating table with a serious resolution to this issue, which has to be agreeing the terms of the JCPOA," said Truss, according to Reuters.

"This is their last chance and it is vital that they do so. We will not allow Iran to acquire a nuclear weapon," she added.

Meanwhile, Iran said on Sunday that European countries had failed to offer constructive proposals to help to revive the 2015 nuclear deal.

"European parties fail to come up with any initiatives to resolve differences over the removal of sanctions (on Iran)," Iran's top negotiator Ali Bagheri Kani said, according to Reuters.

Nuclear talks between Iran and world powers formally resumed in Vienna on Thursday. The talks ended within an hour, though Russia's envoy to the talks said the meeting was productive.

Iran has gradually scaled back its compliance with the 2015 nuclear deal it signed with world powers in response to former US President Donald Trump’s withdrawal from the agreement in May of 2018.

Iran has repeatedly demanded that the US lift sanctions imposed on Iran and also reassure Iran it will not abandon the deal again as a precondition for its returning to compliance with the deal.

Germany's Foreign Minister, Annalena Baerbock, warned on Saturday that time was running out to find a way to revive the 2015 nuclear deal.

"Time is running out. It has shown in the last days that we do not have any progress," she said.

Meanwhile on Saturday, Iranian President Ebrahim Raisi said that Tehran was serious in its nuclear talks in Vienna, adding that the US removing the sanctions imposed on Iran would show that it is serious as well.