WASHINGTON (AP) — The White House is blaming increased tensions in Ukraine on its government for failing to acknowledge its people’s legitimate grievances, and is threatening sanctions if the use of violence continues.

National Security Council spokeswoman Caitlin Hayden says the U.S. is deeply concerned about violence in Kiev. That’s where anti-government protests escalated into fiery street battles with police Sunday in a sharp escalation of Ukraine’s two-month political crisis.