Moscow ? Russia formally proposed to Iran on Saturday that it move its uranium enrichment facilities to Russian territory, raising pressure on the Tehran regime to accept the Western-backed plan for restraining its nuclear program.

Iran insists the program has the sole aim of making fuel for atomic reactors that would generate electricity and denies U.S. charges it is trying to develop nuclear weapons in violation of the Nuclear Nonproliferation Treaty.

Washington and the European Union have warned about taking Tehran before the U.N. Security Council for consideration of sanctions over the dispute. But Russia and China, which have vetoes on the council, oppose referral and the West has stopped short of forcing the matter.

In a diplomatic note to Iran’s government, Russia’s Foreign Ministry said that “an earlier Russian offer to Iran to establish a joint Russian-Iranian enrichment venture in Russia remains valid,” the ministry said. The note was delivered by the Russian Embassy in Tehran.

Iranian officials didn’t immediately comment on the offer. Gholamreza Aghazadeh, head of the Atomic Organization of Iran, dismissed the proposal as unacceptable earlier this month.