Ukrainian First Deputy Prime Minister Vitaliy Yarema has said at a meeting with a delegation of the U.S. Congress that Kyiv expects the U.S. Congress to take more effective measures against Russia.

"The signing by [Russian President] Vladimir Putin on an agreement on the inclusion of Crimea into the Russian Federation causes significant concern. Given this, Ukraine expects the U.S. Congress to take more effective measures against the aggressor," the first deputy prime minister's press service quoted him as saying at the meeting on Sunday.

At the same time, he said that Ukraine was doing everything possible to resolve the problem peacefully and "appreciates U.S. support in guaranteeing the sovereignty and territorial integrity of the Ukrainian state."

According to the press service, the meeting was attended by Senators Kelly Ayotte, Joe Donnelly, Congressman Stephen Lynch and U.S. Ambassador to Ukraine Geoffrey Pyatt.