A spokesman for Vladimir Putin said the two-week old Geneva agreement to defuse the Ukraine was no longer viable after Kiev launched its first serious offensive to retake the rebel-held city of Slavyansk Friday. In Washington, Barack Obama Friday accused Russia of violating international law. Standing alongside German chancellor Angela Merkel, he said the separatists were not peaceful protesters but armed militias. Both leaders warned Moscow that if Russian actions in Ukraine continued, and the May 28 election was disrupted, new sanctions would be imposed – this time on complete Russian sectors.

Two Ukrainian helicopters were shot down Friday over Slavyansk. One pilot was killed and a second captured. Ukraine’s security service said one was brought down by a surface-to-air missile. The rebel militia said Ukrainian troops had launched attacks on several checkpoints, but denied that they had taken control of nine checkpoints around the city. In the southern city of Odessa, three people were killed and 15 injured in clashes between separatists and “Euromaidan” activists.