Ukraine has called for UN-mandated peacekeepers to enforce a shaky cease-fire deal in the country’s east.
At an emergency security meeting on February 18, President Petro Poroshenko said "the best format would be a police mission from the European Union."
Russian-backed separatists denounced the call for peacekeepers, saying their presence would "violate" the truce agreed in Minsk last week.
Ukraine made the call after Ukrainian troops withdrew from the strategic town of Debaltseve following intense fighting.
The rebel advance, which came in spite of the cease-fire, has been widely condemned.
Ukraine and the West have accused Russia of sending in troops and weapons to spearhead the assault on Debaltseve, which Moscow denies.
The White House said Russia has failed to live up to terms of the Minsk deal and is “at risk of greater costs” such as further sanctions.