In Brussels, EU diplomats said the bloc was holding off from imposing further sanctions until it sees whether the Geneva deal works.
The EU has been more cautious than the United States in imposing sanctions on Russia, with some member states worried about antagonizing a country that supplies a third of Europe's gas.
Both sides stressed on Tuesday they wanted to depend less on the other over energy.
Medvedev said Russia was more interested than ever in diversifying its gas exports and described talk of Europe importing U.S. gas as a substitute as "a bluff".
Partly as a result of the Ukraine crisis, the EU is stitching together measures such as raising electricity production from coal and renewables. Russia's top natural gas producer, Gazprom, maintained, however, that Europe still needed its supplies. According to most scenarios, long-term gas demand would increase in the European market, while production there would decline, it said in a statement issued after a board meeting.
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Reuters calculations suggest the EU steps could slash imports from Russia by around 45 billion cubic meters by 2020, worth $18 billion a year, or the equivalent of a quarter of what Russia currently supplies.
During Biden's trip, the United States offered Ukraine a new $50 million aid package to help with economic and political reform. Of that, $11.4 million was earmarked for helping with the election to choose a successor to Yanukovich, the White House said in a statement.
While small in relation to Ukraine's huge needs and a $1 billion loan guarantee already signed with Washington, the package serves to show support for the new authorities following the overthrow of the Kremlin-backed Yanukovich in February.
Biden also had tough words for Kiev, saying it must deal with the endemic graft that has sapped the economy and public faith in the state. "To be very blunt ... you have to fight the cancer of corruption," he told lawmakers.