Foreign Minister Sergey Lavrov said Tuesday that Russia was worried about Iran's intention to renew uranium enrichment activities and said Moscow had called on Tehran to maintain its moratorium on enrichment pending negotiations, Russian news agencies reported. "We are expressing concern over recent information that Iran has expressed the intention to soon renew a series of activities tied with enriching uranium, in spite of the moratorium that was agreed between Iran and the European countries and in spite of the fact that this agreement was confirmed in decisions of the IAEA," the RIA-Novosti news agency quoted Lavrov as saying at a meeting with President Vladimir Putin and other members of the Russian government. President Chirac of France also expressed concern over Iran's nuclear intentions, saying that Iran and North Korea will commit serious mistakes if they ignore the international community's repeated warnings and press forward with contested nuclear programs. Chirac, in a New Year address laying out his foreign policy objectives, said Iran and North Korea have a right to use nuclear energy peacefully, for energy. But the international community must ensure that agreements on nuclear security are not trampled on, he said. "These countries would be committing a grave error if they do not take the hand that we are extending to them," Chirac said. Earlier Tuesday, Iran removed seals on its nuclear research facilities, allowing work to resume despite warnings from Western countries concerned about its nuclear ambitions, Iranian nuclear authorities said. Germany's foreign minister raised doubts Tuesday over the future of European-led negotiations on Iran's nuclear program, saying he planned to consult with French and British colleagues on whether there is any reason to continue with talks. "Tehran has crossed lines which it knew would not remain without consequences," said Frank-Walter Steinmeier. Steinmeier said he had asked the head of the International Atomic Energy Agency to draw up an evaluation of the nuclear threat posed by Iran. "On the basis of this evaluation, I will try this week to coordinate with my British and French colleagues ... to see whether our negotiations still have a basis." Britain's Foreign Secretary Jack Straw also joined the chorus against Iran on Tuesday, saying that Iran had again breached the U.N. nuclear watchdog's resolutions. "We are profoundly concerned that Iran has decided to restart research and development activities related to uranium enrichment," Straw said in a statement. ALSO TUESDAY, Russia's deputy foreign minister, Sergei Kislyak, said a Russian delegation had told Iranian officials that Moscow's offer to enrich uranium on Russian territory and then ship it back to Iran to fuel nuclear power stations still stands and that the Russian side is waiting for an answer, the Interfax news agency reported. That proposal, backed by the European Union and the United States, is meant to ensure that Iran could not misuse the enrichment process to produce nuclear weapons. "Should our Iranian colleagues be interested, we are ready to develop the joint project in order to solve Iran's energy problems," Kislyak was quoted as saying. Lavrov said an Iranian delegation would pay a return visit to Moscow next month to continue the discussions, Interfax reported. He said the talks between a delegation led by Russian Security Council deputy secretary Valentin Sobolev and officials in Tehran had been "serious, professional, detailed and honest." "We stated our concern over Tehran's intention to resume nuclear research and development," Kislyak was quoted as saying. Lavrov said Moscow was coordinating its actions with Germany, Britain and France, Interfax reported. Enrichment is a process that can produce nuclear fuel for reactors or atomic weapons, depending on the degree of enrichment.