Foreign ministers from China, France, Germany, Britain and Russia to discuss with Iranian officials how to keep a 2015 nuclear accord alive after US President Donald Trump abandoned the pact in May.
France said on Friday it was unlikely that European powers would be able to put together an economic package for Iran that would salvage its nuclear deal before November and warned Tehran to stop threatening to break its commitments to the accord.
"They must stop permanently threatening to break their commitments to the nuclear deal," French Foreign MinisterJean-Yves Le Drian told RTL radio before travelling to Vienna for a ministerial meeting on the agreement.
"They must stop the threats so that we can find the solutions so that Iran can have the necessary economic compensations."
He said the European powers but also Russia and China were working on coming up with a financial mechanism to mitigate planned tough US sanctions.
"We are trying to do it before sanctions are imposed at the start of August and then another set of sanctions in November. For the start August it seems a bit short, but we are trying to do it by November," he said.
An Iranian official said that the collapse of nuclear deal would cause further tension in Middle East.