Ukraine's president urged the resumption of an offensive against militants after U.S. Vice President Joe Biden's visit, as an agreement with Russia to ease tensions in the former Soviet republic's east neared collapse.

With eastern Ukraine in control of "terrorists" supported by Russia, the separatists have "crossed the line" after bodies of a local lawmaker and a member of the Batkivshchyna party were found today, acting President Oleksandr Turchynov said in a statement on the parliament website. Biden expressed U.S. support for Ukraine during a visit to Kiev.

With the April 17 accord in tatters, Ukraine is inching closer to a renewed push to dislodge militants in the restive east. The "active phase" of the military operation was suspended four days ago as Ukraine's government pledged to abide by the agreement negotiated in Geneva by Ukraine, the European Union, the U.S., and Russia.