They’ve dined at Dmitry’s country house outside Moscow, and relaxed at Barack’s favorite burger joint in Virginia. The presidents of Russia and the United States “have built an outstanding relationship, and as a consequence, we’ve been able to reset relations,” President Obama declared in May.

Now, Obama is going to have to get used to a new partner--Vladimir Putin--after Medvedev announced he would support his mentor’s return to the presidency. Putin, now prime minister, is expected to easily win the March election.

Early in his presidency, Obama sought to focus on Medvedev, a young lawyer who presented himself as a moderate. The men met numerous times at summits and in Washington and Moscow. In contrast, Obama met only once with Putin, in July 2009--days after declaring the former KGB chief had “one foot” in the Cold War.

Administration officials say that the lack of contact reflects the fact that Medvedev, as president, was in charge of foreign policy. And while senior officials have had limited contact with Putin, they say, the encounters have gone fairly well.

On her March 2010 trip to Moscow, Secretary of State Hillary Rodham Clinton was lectured in public by Putin about trade issues. But Clinton was able to crack Putin’s famously icy reserve in their one-on-one meeting, by raising the subject of the endangered Siberian tiger, one of his passions, officials say. Putin later led Clinton into his private study to show her a map he keeps there of tiger territory in Russia.

When Vice-President Joe Biden met Putin during a trip to Moscow in March, administration officials expected a chilly session. Biden, after all, has close ties to President Mikheil Saakashvili of Georgia, whose nation fought a brief war with Russia in 2008.

Instead, “they had a very constructive and substantive meeting that went on very long,” said a senior administration official, speaking on condition of anonymity because of diplomatic sensitivities. While the two men disagreed about some things--like Georgia--“we expected a different kind of meeting,” he said.

U.S. officials, of course, weren’t unaware of Putin’s outsized behind-the-scenes influence on the Russian government. And they say there is little daylight between Putin and Medvedev on the two major issues that Washington is working on with Moscow at the moment--cooperation on missile defense, and Russia’s accession to the World Trade Organization.

But they may have to get used to a sharper tongue from the Russian leader. Putin, for example, recently criticized Americans for living with such a large national debt. “To a certain extent, they are parasites on the global economy and their own monopoly on the dollar,” he told pro-Kremlin activists.