EU High Representative for Foreign Affairs and Security Policy and European Commission Vice President Federica Mogherini called for spiral of violence in eastern Ukraine to stop.

"The fighting provoked by the continued separatist offensive, notably around Debaltseve, is causing great human suffering and undermines all efforts aimed at a political solution," Mogherini said in a statement circulated in Brussels on Wednesday.

"The shelling of civilians, wherever it happens, is a grave violation of international humanitarian law," Mogherini said.

"Artillery should immediately be withdrawn from residential areas," she said.

Residents of Donbas are striving to flee the region and the humanitarian crisis continues to worsen dramatically in the coldest period of the year, she said.

"Civilians need to be able to leave the conflict zone safely," Mogherini said.

The EU foreign policy chief supported a call by the OSCE Chairperson-in-Office "on all actors in and around the Debaltseve area to establish a local temporary truce for a minimum of three days, taking immediate effect."