German Chancellor Angela Merkel has said a cease-fire agreement was still being violated in eastern Ukraine on a regular basis.
Speaking ahead of talks with Ukrainian President Petro Poroshenko in Berlin on May 13, Merkel said: "Based on the Minsk agreement from February, we have to observe that we are not yet where we want to be. We still don't have a complete cease-fire."
Poroshenko pointed to continued clashes near the Donetsk airport and demanded that international monitors be posted there.
"The heavy weapons must be withdrawn," he added.
Merkel was to brief Poroshenko on her May 10 meeting with Russian President Vladimir Putin.
Kyiv and the West accuse Russia of arming separatists in eastern Ukraine and sending troops there, charges Moscow denies.
More than 6,100 people have been killed in the fighting between government forces and rebels since April 2014.