If Europe can react well to energy woes tied to Ukraine, energy security will be stronger than ever before, the European Commission president said in Brussels.

President Jose Manuel Barroso spoke to delegates at a European energy security conference in Brussels, saying that addressing the issue will test the resolve and determination of members of the European Union.

A crisis that spilled out of Ukraine's uprising in November and subsequent tilt toward the West has put the European energy sector at risk. Russian energy company meets about a quarter of Europe's needs, but the bulk of those supplies run through Ukraine. Mounting debt in Ukraine means it can't pay its gas bills and Russia has said it may cut supplies by June.

In the past, Barroso said, European leaders have been lax on addressing the issue. Europe, however, imports more than 60 percent of its natural gas needs and almost 90 percent of the oil it consumes.

"Reducing energy demand is a fundamental precondition for limiting our energy dependence," he said.

European member states are called to increase energy efficiency by 20 percent from a 1990s benchmark by 2020. European energy policy also calls on a greater share of renewable energy on the region's grid.

"If we agree on these priorities and maintain the momentum that resulted from the Ukrainian wake-up call, Europe will come out of this crisis stronger, more united and more secure than we were before," the president said.