A meeting on Friday between the remaining signatories of the 2015 Iran nuclear deal is the "last chance" to save the accord, Iranian officials said. Iran is threatening to exceed the maximum amount of enriched uranium allowed it by the deal, in retaliation for crippling economic sanctions imposed by the US withdrawing from the pact last year. It is just days away from that limit, diplomats say, and going over it could unravel the accord. Senior officials from Iran and the deal's remaining parties are meeting in Vienna with the aim of saving the pact. European powers are set to announce funding to launch a mechanism for barter trade called Instex, as a way around the US sanctions. Instex would net out amounts at either end but diplomats say it will only be able to handle small volumes of items such as medicine, not the large oil sales Iran that are crucial to Iran's economy. "I think this meeting can be the last chance for the remaining parties ... to gather and see how they can meet their commitments towards Iran," Iranian foreign ministry spokesman Abbas Mousavi said, in comments reported by Iran's Fars news agency. Mr Mousavi said that despite supporting Iran's stance in several statements, the remaining signatories – Britain, China, France, Germany and Russia – had failed to take any action. A European Union diplomat said on Thursday that remaining parties to JCPOA were “scrambling” to find a solution. Anticipating Friday’s joint statement, he said the backing of at least half a dozen European nations could provide Instex with “critical mass.” Still, it was far from certain the development would be enough to placate Iran, he said, asking not to be named discussing the sensitive issue. As the talks kicked off on Friday, seven EU nations expressed support for Instex and the JCPOA, asking Iran "to abide by and fully respect the terms and provisions of the nuclear agreement". "We are working with France, Germany and the United Kingdom, as well as with the European External Action Service and the European Commission, to establish channels to facilitate legitimate trade and financial operations with Iran, one of the foremost of these initiatives being the establishment of Instrument in Support of Trade Exchanges," read the statement from Austria, Belgium, Finland, the Netherlands, Slovenia, Spain and Sweden. Fars also quoted Deputy Foreign Minister Abbas Araqchi, who is in Vienna, as saying Iran had run out of "strategic patience", and adding, "Iran will not tolerate remaining unilaterally committed to the nuclear deal." He said he hoped the Vienna meeting could lead to "tangible" action, the agency said. "We should see how much money can be transferred via Instex," Mr Mousavi said. "If it's an artificial mechanism, Iran will surely not accept it." Iran’s ambassador to the United Nations, Majid Takht Ravanchi, on Thursday said that European nations weren’t working quickly enough to guarantee Iran could continue to trade with them despite US sanctions. “Personally, I don’t think it will be enough,” Ravanchi told reporters in New York. “It took them more than a year to put this in place, and it’s still not operational. It’s as if you have a beautiful car, you enjoy looking at it, but there’s no gas inside. So all you can do is look.” Trade between Germany and Iran has collapsed under the impact of US sanctions, data published by Funke newspapers showed, supporting Iran's assertion that Europe is failing to help preserve the nuclear non-proliferation deal it signed. French President Emmanuel Macron said on Thursday he would try to convince US President Donald Trump to suspend some sanctions on Iran to allow for negotiations to help defuse the crisis. Tehran has so far rejected Washington's offers of talks to negotiate a new deal, and tensions between the two countries have risen following the downing of a US drone in the Strait of Hormuz by Iran and attacks on international shipping in the region that the US has blamed on Iran. Mr Trump pulled the US out of the deal in May last year, saying it was flawed and did not address Iran's missile programme or its support for terrorism in the region.