Igor Ivanov, who is currently on a working visit to the United States, said all six mediating countries in the nuclear dispute with Iran firmly agree on the issue that it is unacceptable for Iran to possess nuclear weapons.
"It is important to preserve the unity of the [Iran] six, as a split could complicate a political resolution," Ivanov said.
The original proposal for sanctions on Iran's nuclear program, drawn up by Britain, France, and Germany, met with resistance from Russia, which has taken a softer line on sanctions against Iran.
Diplomats said earlier that the new European proposal for sanctions aim to take into account Russian objections.
Ivanov reiterated that Russia's position is that Tehran has a legal right to civilian nuclear energy, but that it has to provide the international community with guarantees that it will not violate non-proliferation agreements.
Iran has dismissed international suspicion that it plans to build nuclear weapons, citing its right to pursue nuclear energy for civilian purposes under the Nuclear Non-Proliferation Treaty.