Russian President Dmitri Medvedev is calling on Iran to explain its nuclear program and to fully cooperate with the international community.
Mr. Medvedev said Thursday that though the two countries have an active trade partnership, Russia is not indifferent to the way Iran is developing its nuclear program.
Russia is traditionally a diplomatic and economic ally of Iran, and is helping Tehran build a nuclear power plant at Bushehr. But Moscow has hardened its position against Iran's other nuclear activities in recent weeks.
On Monday, Mr. Medvedev said Iran is getting closer to having the potential to build a nuclear weapon. Russia last month joined other world powers in approving a fourth set of U.N. sanctions on Iran for its refusal to suspend its uranium enrichment operations.
Western powers accuse Iran of seeking to build nuclear weapons under the cover of its civilian nuclear program -- a charge repeatedly denied by Iranian authorities.
Some information for this report was provided by AP, AFP and Reuters.