Russia's Foreign Minister Sergey Lavrov said Tuesday on a trip to Iran that unilateral sanctions - such as those recently imposed by the United States - will not help solve the Iranian nuclear problem. Lavrov's remark came as the Russian, on a surprise visit to Teheran, met Iranian President Mahmoud Ahmadinejad for talks on the Iranian nuclear program. Earlier in the day, Ahmadinejad shrugged off a new round of US sanctions targeting Iran, saying the country would not succumb to pressure from Washington, Iranian media reported. Iranian state television released no details on the Lavrov-Ahmadinejad talks, but Russian news reports said Lavrov warned that unilateral sanctions could undermine a collective effort by the international community to get Iran to halt its controversial uranium enrichment. "Unilateral actions taken now regarding trade and economic sanctions against Iran won't help to continue collective efforts," Lavrov was quoted as saying by the ITAR-Tass and Interfax news agencies, in an apparent reference to the US sanctions against Iran announced last week. For his part, Ahmadinejad ridiculed the US sanctions as hollow, and said the move showed the "Americans are not able to harm us." The remarks were the Iranian leader's first reaction to Washington's move. "Americans think that they can force the Iranian nation to give in by resorting to unilateral economic sanctions," Ahmadinejad told a group of students, according to the official news agency, IRNA. "Enemies have understood that they are not able to thwart the progress of the Iranian nation." Lavrov earlier Tuesday met his Iranian counterpart, Manouchehr Mottaki and discussed bilateral relations, IRNA also reported. Lavrov's visit to Teheran was his second in two weeks - an unprecedented move by a Russian official, indicating stepped up Moscow efforts to influence Iran. "We stand exclusively for a peaceful settlement," Lavrov said, adding he had told Mottaki about the need for more work in Iran by the UN nuclear watchdog agency to "clarify questions which the international community has regarding past Iranian nuclear programs." Lavrov also said he underlined the "need for a quick answer to these questions to restore trust in the exclusively peaceful character of Iran's activities in the sphere of nuclear energy." Earlier in October, Lavrov accompanied Russian President Vladimir Putin on a landmark one day visit here, the first Kremlin leader to come since 1943. At the time, Putin was said to have put forth a proposal to resolve Teheran's standoff with the West over its nuclear program but the details of that proposal were not revealed. Later Ahmadinejad disputed the report and said Putin had not spoken about the nuclear issue. Since then, the new US imposed sanctions on Iran ban dealings with a host of companies connected to Iran's Revolutionary Guard Corps, an elite force that has extensive business holdings in oil, construction and other sectors. The sanctions prohibit American companies from working with those companies, but also put pressure on international firms and banks not to deal with them as well. The US and some of its allies claim Iran plans to obtain a nuclear weapon. Iran denies it is seeking nuclear arms, insisting its program aims only to produce electricity. Washington also accuses forces affiliated to the Guard Corps of arming insurgents who targets American soldiers in Iraq. Iran again denied the claim on Tuesday. "We are not happy about the loss of any human being even American soldiers in Iraq and we are worrying (about it)," said Mottaki, according to state TV. But Mottaki also warned the US not to list the entire Guard Corps as a terrorist organization. "If you in an unprecedented decision call the army of a country terrorist, you have to expect consequences," he said. Iran is counting on international support from Russia, and also China, to prevent harsher separate sanctions imposed by the UN Security Council. Moscow and Beijing, both permanent Security Council members, are resisting US calls for a third round of sanctions and have come out against military action - though both have urged Iran to comply with UN demands for a halt in enrichment. The process can be used to produce either fuel for a nuclear reactor or a nuclear warhead. Russia is building Iran's first nuclear power plant in southern Iranian port of Bushehr. Putin has said he sees no evidence Iran is building a weapon but has said Iran should not be allowed to do so. Russia and the other permanent Security Council members, plus Germany, have been working together to try to find a way to get Iran to abandon enrichment. The group has offered a package of economic and political rewards to Iran if it agrees to suspend enrichment but Iran has rejected that proposal.