Lavrov spoke following talks with U.S. Secretary of State Hillary Rodham Clinton, who is trying to gauge Moscow's willingness to join the U.S. in imposing sanctions if Iran fails to come clean on its nuclear activities.
Lavrov said Russia's position is that under current conditions even the threat of sanctions against Iran would be counterproductive.
Clinton said the U.S. agreed it was important to pursue diplomacy with Iran.
"At the same time ... we have always looked at the potential of sanctions in the event we are not successful" in persuading Iran to comply, she said at a joint news conference.
Iran insists it has the right to a full domestic nuclear enrichment program and maintains it is only for peaceful purposes, such as energy production.
Clinton's visit to Moscow is her first since becoming America's top diplomat and since President Barack Obama - who visited Russia in July - vowed to "reset" U.S.-Russia relations. She was to meet with Russian President Dmitry Medvedev later Tuesday.
Beyond Iran, Lavrov said the U.S. and Russia have made "considerable" progress toward reaching agreement on a new strategic arms treaty.
The 1991 Strategic Arms Reduction Treaty, or START, expires in December and negotiators have been racing to reach agreement on a successor.
The two diplomats also discussed a recent Obama administration decision to scale back a Bush-era proposal for an anti-missile shield in Europe.
Also on the agenda are Afghanistan, nuclear-armed North Korea, NATO expansion, the situation in Georgia after its conflict with Russia last year, human rights and arms control.