German Chancellor Angela Merkel's office said the German leader spoke by phone Monday night with Russian President Vladimir Putin, Ukrainian President Petro Poroshenko and French President Francois Hollande.
A 2015 peace deal brokered by France and Germany has helped reduce the scale of fighting, but violence has continued and attempts at a political settlement have failed.
The German statement early Tuesday said the four leaders stressed their commitment to implementing the "security and political aspects of the deal," underlined the importance of respecting a cease-fire and urged progress on the exchange of prisoners, the Associated Press reported.
They voiced hope that the four-country format will continue under France's next president.