BRUSSELS, March 26 -- The leaders of European Union and United States vowed on Wednesday to support Ukraine and "intensify sanctions" on Russia if things "further escalating."

"If the Russian leadership thought the world would not care about Ukraine, they clearly miscalculated," Obama said at a press conference after the EU-U.S. summit meeting.

"There is still a way for Russia to work with Ukraine," Obama added.

"We support Ukraine", and in case of further escalation, the EU and the U.S. are ready to "intensify sanctions," said European Council President Herman Van Rompuy in the same conference.

Van Rompuy also said that sanctions are a positive incentive to seek a diplomatic solution.

While the president of European Commission Jose Manuel Barroso called the Ukraine crisis a "wake up call" for the EU that the EU need to become less dependent from energy coming from "difficult spots", indicating from Russia.