BRUSSELS - The European Union on Wednesday condemned a rebel offensive against the strategic town of Debaltseve in eastern Ukraine as a "clear violation" of an internationally-backed ceasefire.
"The actions by the Russia-backed separatists in Debaltseve are a clear violation of the ceasefire," the EU's foreign affairs head Federica Mogherini said in a statement.
"The separatists must stop all military activities," Mogherini added, only moments after Ukrainian President Petro Poroshenko announced that beleaguered Kiev troops had withdrawn from the flashpoint town.
"Safe passage for all those who want to leave the area must also be ensured," Mogherini said.
Journalists and monitors from the Organisation for Security and Cooperation in Europe tasked with overseeing the ceasefire have been prevented by rebels from entering the town.
Some 5,000 civilians are thought to be trapped there, many sheltering from the brutal winter in cellars with little water or food.
"The EU calls for immediate access of the OSCE Special Monitoring Mission to assume its monitoring and verification functions in and around Debaltseve and to any other site the Mission needs to go," the statement said.
"The EU stands ready to take appropriate action in case the fighting and other negative developments in violation of the Minsk agreements continue."
The EU warned Russia last week it was prepared to impose more sanctions if the new Ukraine peace pact signed in the Belarusian capital last week was breached.
Brussels first imposed targeted sanctions after Russia's annexation of Crimea in March 2014 but adopted tougher economic measures after the shooting down of Malaysia Airlines flight MH17 over Ukraine in July.