Tehran and six world powers are on the verge of agreeing to revive the 2015 Iran nuclear deal, the head of the International Atomic Energy Agency said Tuesday.

In an interview with the France 24 English-language television station, Rafael Mariano Grossi welcomed Russian Foreign Minister Sergei Lavrov’s announcement that Moscow had received assurances from the United States that sanctions against Russia over Ukraine would not interfere in implementing the 2015 deal, the JCPOA (Joint Comprehensive Plan of Action).

Contrary to claims by some US and western European officials, Grossi said “the problems that emerged in the past few days were real” as sanctions against Russia over Ukraine had cast doubt on “some of the actions and activities contemplated under the JCPOA.”

“The JCPOA is an extremely complex instrument that has a number of limitations – things that Iran shouldn’t or couldn’t do,” Grossi explained. “But at the same time, it has some incentives, some technical cooperation projects and things that could be facilitated in Iran under the inspectors of the IAEA, and carried out in cooperation mainly with China and Russia…All of a sudden, these activities of commercial nature that require buying equipment, exchanging expertise, etc appeared to be in doubt.”

The US has in recent years employed third-party sanctions against Iran, leaving open anyone dealing with Tehran to punitive US action. The IAEA would play a role monitoring a restored JCPOA, with the enhanced inspection powers under the agreement. “I hope we can have this agreement soon, and start working - my inspectors are ready to go,” Grossi maintained.