Kiev and pro-Kremlin insurgents have discussed arranging new talks after 24 people died in a wave of east Ukrainian violence that forced Europe to extend targeted sanctions against Russia.
Friday's meeting in Belarusian capital Minsk comes with clashes in a war that has killed 5100 people peaking after a month-long lull that instilled hopes of peace returning to the lands on European Union's eastern frontier.
Rebel leaders last week pulled out of all peace talks and announced a new offensive that was followed by a rocket assault on the strategic port of Mariupol in which 31 civilians died.
The insurgents later distanced themselves from the bloodshed despite being blamed for it by international monitors on site.
But they have followed through on their threat to push into potentially lucrative eastern industrial lands that still answer to Kiev's pro-Western government under a September truce deal.
Local officials and the Kiev military said 19 civilians and five Ukrainian soldiers died in the latest wave of clashes across the separatist Lugansk and Donetsk regions since Thursday afternoon.
The worst violence was around Debaltseve - a key government-held town of 25,000 people that was built around a railroad connecting the two rebel centres of the Russian-speaking southeast.
Donetsk insurgency commander Alexander Zakharchenko told Russian state television that Ukrainian troops in the town were "surrounded" and unable to receive supplies or send their wounded for treatment in regional hospitals.
"Surrender and you will live," said the rebel.
"I promise you that you will all return home."
EU leaders hope the Minsk meeting will help revive the September ceasefire and eventually mend the West's tattered relations with Russia - the alleged mastermind and main weapons supplier of the war.
The 28-nation bloc on Thursday extended through September the first wave of targeted sanctions it slapped on Moscow and Crimean leaders in the wake of Russia's March seizure of the Black Sea peninsula from Ukraine.
EU foreign ministers also agreed to start work on further "appropriate action" if Moscow and the eastern gunmen continued breaching the original terms of the September truce.
Russia flatly denies fuelling the uprising in reprisal for last February's ouster in Kiev of a Kremlin-backed leader and the ex-Soviet republic's subsequent decision to strike a new EU alliance and seek future NATO membership.
Moscow on Friday accused Brussels of adopting a "one-side reading" of the conflict and warned that further penalties would only backfire.
"It is time for the European Union to really think about the lack of prospects for the sanctions standoff, which only harms the people and the economies of our countries," the Russian foreign ministry said.
The sanctions in Brussels were extended - but not substantially toughened - only moments after Belarus confirmed all sides' agreement to take part in new peace talks.
