Sergei Lavrov was responding to remarks from Manouchehr Mottaki, his Iranian counterpart, that Russia and China "had officially told us ... [of] their opposition to sanctions and military attacks" against the Islamic Republic.
"We have made no such announcements. In such an important and serious area like nuclear non-proliferation, we can make a decision only based on the opinions of experts," Lavrov told reporters.
"The inspections that have been held in Iran do not allow us to conclude that Iran has the technology to create weapons of mass destruction. But, on the other hand, these inspections do not allow us to make the opposition conclusion."
He spoke a day after discussion started between the five veto-holding members of the UN Security Council - Britain, China, France, Russia and the United States - over a resolution demanding that Iran curb its nuclear programme.
Iran says that it wants nuclear
technology for civilian purposes
Britain, France and Germany, which are sponsoring the resolution, want it adopted by Monday and were due to meet again on Friday to push the case forward.
The US and Europe allege that Iran is trying to acquire nuclear weaponry under cover of a civilian power network currently being built with Russian help.
Iran says it needs enriched uranium as fuel for its civilian programme and refuses to stop the work.
Abdullah Gul, Turkey's foreign minister, said Mahmoud Ahmadinejad, Iran's president, should compromise.
"All of us should make efforts for peace. We should insist on diplomatic means and find a compromise," he said.
Iran's neighbours are nervous about the potential effect in the region of sanctions or any other deterioration. "The most difficult situation will be for neighbouring countries," Elmar Mammadyarov, Azerbaijan's foreign minister, said on Thursday.
"We are set on continuing our path to industrial production of nuclear fuel for our nuclear power stations in line with international regulations and under the supervision of the IAEA"
Ahmadinejad, the Iranian president
Speaking at a regional conference in the Azeri capital Baku, he repeated Iran's view that its nuclear programme was being undertaken in full accordance with international law and was open to international checks.
Iran has said it wants a negotiated end to the dispute, but rejects calls to freeze enrichment.
"We are set on continuing our path to industrial production of nuclear fuel for our nuclear power stations in line with international regulations and under the supervision of the IAEA [UN nuclear watchdog]," Ahmadinejad said.
Russia has previously opposed sanctions against Tehran, saying they will be counterproductive.