Ukrainian President Petro Poroshenko says he's ready to enact a bilateral ceasefire.
Poroshenko has made the suggestion in a telephone conversation with German Chancellor Angela Merkel.
Russian President Vladimir Putin has also spoken with Merkel and French President Francois Hollande.
He's used the conversation to re-issue his call for a ceasefire.
Russian Foreign Ministry spokesperson Alexander Lukashevich contends the fighting in eastern Ukraine has been escalating.
"We see for ourselves that the ceasefire hasn't happened. But rather, there has been a toughening of the situation, a toughening and an expansion of the punitive operation of the Ukrainian forces. This gives a rise to regrets."
Ukrainian authorities say 23 of the 36 districts seized by militants in the eastern regions of Donetsk and Luhansk have been retaken by the Ukrainian army.
