Russia expects the leaders of Germany and France to put more pressure on Ukrainian President Petro Poroshenko to implement the February peace plan for east Ukraine, Foreign Minister Sergei Lavrov said on Wednesday.

"It is necessary in our view to mount additional pressure on Kiev," Lavrov told reporters, adding he expected Germany's Angela Merkel and France's Francois Hollande to act accordingly as they are among the guarantors of the peace agreement.

The leaders of France, Germany and Ukraine will meet in Berlin on Monday in a bid to end a new wave of violence in east Ukraine.

Kiev and the insurgents on Monday reported the deaths of at least 10 soldiers and civilians - a dramatic escalation that sparked international condemnation and marked the worst bloodshed in more than a month.

Russian President Vladimir Putin pinned the upsurge on alleged preparations by Kiev to grab back territories it had lost in the course of the 16-month war.

"Unfortunately, we are now witnessing an escalation whose blame lies not on the rebels but on their foes," Russian news agencies quoted Putin as saying.

"I hope that things will not lead to large-scale violence."

But Ukrainian army spokesperson Vladyslav Seleznyov accused "Russia of trying to pile additional pressure on Ukraine."

"This once again proves that the [insurgents] are not looking for a peaceful way out of this conflict," he said in Kiev.

The Ukrainian army on Tuesday reported the death of one serviceman and the injury of another in the provinces of Lugansk and Donetsk.

But the military also noted a "sharp drop-off in the number of provocative attacks on Ukrainian positions."

Some separatist offensives have previously been halted by strong Western criticism of Russia - an increasingly isolated giant that faces the threat of even stronger Western sanctions for its alleged support of most rebel campaigns.