A recent spike in fighting between Ukraine's army and Russian-backed rebels has resulted in casualties on both sides, despite ceasefire deals supposedly being in place.
"There is no alternative to an exclusively peaceful settlement of the conflict," German Chancellor Angela Merkel and French President Emmanuel Macron said in a statement issued by the Elysee, referring to "the recent unacceptable increase of ceasefire violations".
"It is necessary to implement agreements on disengagement and the withdrawal of heavy weapons behind the agreed withdrawal lines, withdrawal of tanks, artillery and mortars to the agreed storage sites," the statement added, listing requirements to end the conflict.
It said the two leaders "urge the parties to face their responsibilities and to implement as soon as possible the decisions they have already agreed upon, in order to alleviate the suffering of the populations most affected by the present situation."
A ceasefire was agreed in Minsk in February 2015 as part of a broader peace plan, but its terms haven't been fulfilled.
Violence has frequently broken out and UNICEF this month warned that hundreds of thousands of children are at imminent risk of being hit by mines and other explosive weapons in the war-torn east.
The conflict in the former Soviet republic broke out in April 2014 and has claimed more than 10,000 lives.