Ukrainian President Petro Poroshenko has expressed gratefulness to leaders of the European Union (EU) for support of Ukraine and extension of sanctions against Russia.

"I am deeply grateful to all our friends in the EU for the unbreakable unity and solidarity with Ukraine," Poroshenko wrote on his Facebook page.

"I thank Chancellor Angela Merkel and President Emmanuel Macron for an objective assessment of the situation in the Donbass and clear responsibility of the Kremlin for not complying with the Minsk Agreements," he wrote.

"The price for aggression would grow further if Russia continues undermining the peace process and ignore its obligations," he said.

Poroshenko expressed confidence that "with a common front we will be able to force the aggressor to respect international law and ensure the restoration of the sovereignty and territorial integrity of Ukraine!"