It is not yet time for sanctions against Iran, but the US may consider a firmer course of action if diplomatic avenues proved to be fruitless, US Secretary of State Hilary Rodham Clinton said in Moscow on Tuesday. "[Immediate implementation of sanctions] is not a conclusion we have reached. And we want to be very clear that it is our preference that Iran works with the international community," she said . Clinton's visit to Moscow, her first trip since becoming America's top diplomat, was intended to gauge Moscow's willingness to join the US in imposing sanctions. However, Russian Foreign Minister Sergei Lavrov declared earlier on Tuesday that threatening Teheran with more sanctions would be counterproductive, resisting Clinton's efforts to win agreement for tougher measures if Iran fails to prove its nuclear program is peaceful. Lavrov said Russia's position is that under current conditions even the threat of sanctions against Iran would be counterproductive, while Clinton said the US agreed it was important to pursue diplomacy. "At the same time that we are very vigorously pursuing this track, we are aware that we might not be as successful as we need to be, so we have always looked at the potential of sanctions in the event we are not successful and cannot assure ourselves and others that Iran has decided not to pursue nuclear weapons," 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. US President Barack Obama - who visited Russia in July - has vowed to "reset" US-Russia relations. On Tuesday, Clinton apologized for missing that meeting because of a broken elbow. "But now both my elbow and our relationships are reset and we're moving forward, which I greatly welcome," she said. She was to meet with Russian President Dmitry Medvedev later Tuesday. Beyond Iran, Lavrov said US and Russia negotiators 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 possible cooperation on missile defense following Obama's decision not to proceed with Bush-administration plans to base such a system in eastern Europe. Russia has welcomed Obama's new approach, but has said it was eager for more detailed information. Clinton said the US would be as transparent as possible. "We want to ensure that every question that the Russian military or Russian government asks is answered," she said, calling missile defense "another area for deep cooperation between our countries." Also on the agenda were Afghanistan, nuclear-armed North Korea, NATO expansion, the situation in Georgia after its conflict with Russia last year, human rights and arms control. Iran is already under three sets of UN sanctions. Russia and China have balked at imposing new penalties on Iran, although Medvedev has hinted that the Russian position might be shifting after Tehran disclosed a previously secret uranium enrichment site near the holy city of Qom. Medvedev said last month that while sanctions are rarely productive "in some cases they are inevitable." Lavrov stressed Tuesday the president meant that sanctions would be considered only when all political and diplomatic efforts are exhausted. Sanctions became a harder sell after Iran agreed to allow UN inspectors to visit the Qom site and agreed, in principle, to send most of its low-enriched uranium to Russia for reprocessing.