“We are concerned about this increased separatist violence,” Harf said at a press briefing, noting the Organization for Security and Co-operation in Europe special monitoring mission reported more than 150 ceasefire violations in the past week.
The State Department said the independence supporters in eastern Ukraine are backed by Russia and called on Moscow to cease military support, restore Ukrainian sovereignty over the border, release hostages and reach a peaceful end to months of fighting in eastern Ukraine in line with the Minsk agreement.
A ceasefire has been in place in the war-torn eastern Ukrainian regions since September 9. However, the conflicting sides have repeatedly accused each other of violating the truce.
The conflict in eastern Ukraine erupted when Kiev launched military operations against independence supporters who refused to recognize the legitimacy of the new Ukrainian government that came to power after a February coup.