Iran’s nuclear deal with world powers is in danger of “falling apart" without the compliance of the United States and the European Union, Russia's foreign minister warned Monday after meeting with his Iranian counterpart in Moscow.

The 2015 deal between Iran and Britain, China, France, Germany, Russia and the United States lifted sanctions on Iran in exchange for limits on its nuclear program. The U.S. Withdrew from the accord last year and imposed crippling economic sanctions that block Iran from selling crude oil abroad.

“Because of the destructive line that Washington keeps towing, this important achievement of international diplomacy... Is in danger of falling apart,” Russian Foreign Minister Sergei Lavrov said, adding that “colleagues from the European Union” were not fully complying with the agreement either. In response to the US sanctions, Iran has pressured the European signatories to find a way to limit the impact on the Iranian economy.

Tehran has slowly inched toward ceasing its own compliance with the terms of the deal. Last week, for example, the country began new operations at a heavy water nuclear reactor.

Iran's moves have been condemned by Western governments as unwelcome and escalating tensions in the region, while Russia and China have repeatedly blamed the US.

After meeting with Iranian Foreign Minister Javad Zarif on Monday, Lavrov said Russia would demand full compliance from both the U.S. And the EU, in which case Iran would be able to return to fulfilling its obligations in accordance with the deal. Otherwise the agreement should be considered “no longer existing,” he said.