German Chancellor Angela Merkel on Sunday said there was still no genuine ceasefire in eastern Ukraine as she paid a visit to Moscow to commemorate millions of Soviet soldiers and civilians who died in WWII.

"We still do not have a ceasefire," Merkel said through a translator, speaking after talks with Russian President Vladimir Putin.

"There are a lot of violations on the part of separatists," the German leader said, citing information from international observers.

"Every day we get OSCE reports that explain quite objectively why this ceasefire isn't observed," Merkel said.

"This process is very complex, we hoped that ceasefire would be reached. Unfortunately that did not happen."

In February, Merkel and French President Francois Hollande helped broker a peace deal for Ukraine in a last-ditch effort to stop months of fighting between pro-Russian separatists and Kiev forces.

But Kiev and the insurgents accuse each other of continuing to violate the ceasefire deal despite claims that they have withdrawn heavy weapons from the frontline in accordance with the agreement.

Merkel said the humanitarian situation remained dire, noting that a prisoner exchange was not yet complete.

"We have to do everything to improve this situation."

Putin for his part said he and Merkel did not see eye to eye on the Ukraine crisis but pointed to an improvement on the ground.

"In my view, there is every ground to believe that, with difficulties but all the same, the Minsk process is moving," he said, referring to the peace deal.

"Despite all the problems in eastern Ukraine it has become calmer."

"As for grievances over fulfilment or non-fulfilment of the Minsk agreements, there are grievances on both sides," Putin added.

The conflict has killed more than 6,100 people and displaced a million more.