France said on Tuesday that there had been some progress in negotiations related to Iran"s compliance on nuclear issues, but warned that there remained a lot still to do within a short time frame if efforts to revive a 2015 accord were to succeed. Talks resumed in Vienna on May 7 with the remaining parties to the deal - Iran, Russia, China, France, Britain and Germany - meeting in the basement of a luxury hotel, and the United States based in another hotel across the street. Iran has refused to hold direct meetings with the United States on how to resume compliance with the deal, which former President Donald Trump abandoned in 2018, prompting Iran to begin violating its terms about a year later. "The discussions that resumed on May 7 in Vienna have led to some initial progress on the nuclear issue," France"s Foreign Ministry Spokeswoman Agnes von der Muhll told reporters without elaborating. "Nevertheless, major disagreements remain on some key points that must be ironed out in order to reach an agreement providing for the return of Iran and the United States and their full implementation of the JCPoA. There is still a lot to do, within very tight deadlines." The crux of the agreement was that Iran committed to rein in its nuclear programme to make it harder to obtain the fissile material for a nuclear weapon in return for relief from U.S., EU and U.N. sanctions. Officials have said they hope to reach a deal by May 21, when an agreement between Tehran and the U.N. nuclear watchdog on continued monitoring of some Iranian nuclear activities is due to expire. Diplomats have said they believe there had been sufficient progress in the Vienna talks that an extension of the monitoring accord between Tehran and the U.N. agency was likely even if the modalities would still need to be worked out. "If an agreement on Iran’s resumption of its commitments is not reached before the expiration of the bilateral technical arrangement between Iran and the Agency, they will have to agree on its extension," Von der Muhll said.