The United States is concerned about the escalation of violence in eastern Ukraine and calls for immediately resuming the ceasefire and ensuring OSCE monitors' access.

"The United States is deeply concerned with the recent spike in violence in eastern Ukraine around Avdiivka-Yasynuvata," U.S. Department of State Spokesperson Mark Toner said in a statement on Tuesday.

"To avert a larger humanitarian crisis, we call for an immediate, sustained ceasefire and full and unfettered access for OSCE monitors," the statement says.

"We also reaffirm U.S. support for full implementation of the Minsk agreements," it says.