France said on Tuesday that progress was being made in negotiations on Iran’s nuclear compliance, but advised that there was still a great deal to be done in the brief term if efforts were to succeed in reinvigorating the 2015 agreement.

The Vienna talks were resumed on 7 May in a hotel basement and in the United States in a different hotel across the street with the rest of the parties to the deal, including Iran, Russia, China, France, Britain and Germany.

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 said they hoped to conclude an agreement regarding the continued monitoring of Iranian nuclear activities before 21 May when an agreement between Tehran and the U.N. nuclear watchdog expires.

Diplomats said they thought that sufficient progress had taken place in the Vienna talks, that even when the methods still needed to be worked out, an extension of the monitoring agreement between Tehran and the United Nations Agency was likely.

“If an accord is not reached between Iran and the agency on the resumption of its obligations, they will have to agree upon its extension before the expiry of the bilateral technical arrangement,” Von der Muhll said.