Russia, which is building Iran's first nuclear power plant, has resisted the push by the US and its allies for stronger UN sanctions against Tehran and strongly warned Washington against using force.
"Putin's trip to Tehran is a show of Russia's independence in global affairs. Putin, who approaches the end of his term, wants to demonstrate that he wouldn't cave in to the US pressure," said Alexander Pikayev, an expert on Iran with Russia's Institute for World Economy and International Relations.
Putin emphasized Monday that he would negotiate in Tehran on behalf of the five permanent UN Security Council members -- United States, Russia, China, Britain and France -- and Germany, a group that has led efforts to resolve the stalemate with Tehran.
He said the group "can and must be patient" in dealing with the Iranian leadership.
"If we have a chance to maintain such direct contact, we will do it expecting a positive and, I will stress, joint result," Putin said. "Because Russia has worked and intends to continue to work with partners in Europe and the United States to achieve a common goal."
In Washington, State Department spokesman Tom Casey said the US government expected Putin to "convey the concerns shared by all of us about the failure of Iran to comply with the international community's requirements concerning its nuclear program."
Putin's schedule called for meetings with Iranian President Mahmoud Ahmadinejad and the country's supreme leader, Ali Khamenei. He also was to participate in a meeting Tuesday of the leaders of nations bordering the Caspian Sea.
