With a repeatedly violated weeklong cease-fire nearly over, Ukrainian President Petro Poroshenko on Thursday called on Russia to make genuine efforts to stop the fighting between separatists and Ukrainian government troops.
"Support the peace plan with deeds, not words," Poroshenko urged Russia in a speech at the Council of Europe parliament building in Strasbourg, France.
But the appeal did little to allay fears among those living in the embattled areas of eastern Ukraine that fighting would intensify when Kiev's unilateral cease-fire expired early Friday.
Ukrainian border guards reported miles-long lines of cars at the Izvaryne crossing into Russia. More than 90,000 arrivals from Ukraine had already been registered by the Russian Migration Service as of last week, the government reported, although most said they were only temporarily relocating.
Ukrainian officials have accused Russian President Vladimir Putin of arming and instigating pro-Russia separatists who in recent months have seized a dozen towns and cities in eastern Ukraine and declared the territory independent of rule from Kiev.
Putin has denied backing the rebellion in the largely Russian-speaking eastern regions, although many of its leaders are Russian citizens and veterans of other regional conflicts in former Soviet territory.
More than 400 people have been killed in the conflict between pro-Russia gunmen and Ukraine's security forces, officials said.
Secretary of State John F. Kerry and German Chancellor Angela Merkel also appealed Thursday for Putin, who publicly said he supported the cease-fire, to use his influence with the separatists to halt the bloodshed or face another barrage of economic sanctions.
"It is critical for Russia to show in the next hours, literally, that they're moving to help disarm the separatists, to encourage them to disarm," Kerry said after meeting with his French counterpart in Paris.
Merkel called Putin to make the same point. German and Russian government accounts of the conversation quoted her as telling the Kremlin leader he had to demonstrate "in the coming hours" that he was making sincere efforts to quell the fighting or the European Union leaders meeting in Brussels on Friday would be forced to consider additional sanctions.
Poroshenko will also be at the EU meeting in Brussels on Friday to sign an association agreement with the 28-nation bloc that is intended to realign the Ukrainian economy with western trading partners and navigate a path to eventual membership in the alliance.
It was the decision by Poroshenko's predecessor, Viktor Yanukovich, to scrap the EU association agreement that sparked a rebellion among European-leaning Ukrainians and led Kremlin ally Yanukovich to flee to Russia in February.
Russia opposes Ukraine's shift toward Western Europe as it is expected to weaken Kremlin influence over affairs in the neighboring former Soviet republic, where about one in four citizens is Russian or Russian-speaking.