US President Barack Obama has told the European Union it cannot rely on the United States alone to reduce its dependency on Russian energy.
EU membs rely on Russia for about a third of their oil and gas, but there are concerns about security of supply as relations chill over Russia's seizure of Crimea from Ukraine.
Mr Obama is visiting Brussels to discuss trade relations and the Ukraine crisis.
EU officials pressed him to step up US gas exports, but he told them they need to develop their own resources.
EU ambassador to Washington Jose Vale de Almeida quoted Mr Obama as telling them:
"You cannot just rely on other people's energy, even if it has some costs, some downside," in a clear reference to opposition in parts of Europe on environmental grounds to nuclear power and the fracking method of gas extraction.
The issue will be discussed next week at a special meeting of EU and US energy ministers.
"Once we have a trade agreement in place, export licences for projects for liquefied natural gas destined to Europe would be much easier, something that is obviously relevant in today's geopolitical environment," Mr Obama said after the meeting, adding that it could not happen overnight.