"Iran is a separate problem. This problem is first and foremost a problem of ensuring that the non-proliferation regime is not being violated," Sergei Lavrov said in a live interview with RIA Novosti, the Voice of Russia radio and the Russia Today TV channel.
Media last month cited unnamed senior officials in Washington saying that President Barack Obama could drop the plans to place a missile shield in Central Europe if Russia helps to persuade Iran to halt uranium enrichment activities. Both Washington and Moscow have officially denied the possibility of such a deal.
Washington's plans to place a radar in the Czech Republic and interceptors in Poland, strongly opposed by Russia, have been a major source of tension in the countries' relations. President Obama recently said the plans would remain in place as long as Iran persists with its nuclear ambitions.
Lavrov said Iran must prove that its nuclear program is intended only for electric power generation.
"Iran must convince all of us of the exclusively peaceful nature of its nuclear program."
However, he said that so far "there is no evidence that the program has military goals. Although several countries and the IAEA [the UN nuclear watchdog] have questions that Iran needs to clarify."
The U.S. and other Western powers suspect Iran of seeking to build nuclear warheads under the cover of a civilian nuclear program.
The country is under three sets of relatively mild sanctions over its refusal to suspend uranium enrichment, needed both in weapons production and nuclear power generation. Russia and China have resisted harsher punishment for the country, using their vetoes at the Security Council.
Lavrov welcomed the decision reached in London on Wednesday by the six countries negotiating the Iranian nuclear problem to carry on talks with Iran, as well as Obama's pledge of greater engagement in the negotiations than his predecessor.
"The fact that the Obama administration was ready from the outset to sit at the table and discuss all issues that I have mentioned - this is a very positive development, and I hope that it will allow us to more effectively achieve a swift political and diplomatic regulation of the Iranian nuclear situation," he said.
Britain, Germany, China, Russia, France and the United States asked the EU foreign policy chief, Javier Solana, to invite Iran's leadership to meet with the Iran Six to try to find a diplomatic solution to the dispute.
