Russian President Vladimir Putin has called on Ukraine's leadership and rebels to start genuine dialogue, saying Kiev should halt military operations and guarantee the rights of Russian speakers in the separatist east.
"It's necessary to start detailed, substantial dialogue," Mr Putin told reporters, adding Moscow would support a peace plan drawn up by the Ukrainian leader.
"Russia will certainly support these intentions. But at the end of the day the most important thing is a political process.
"It's important for dialogue between all warring parties to originate on the basis of this peace plan," Mr Putin said in televised remarks.
Mr Putin said artillery was used in overnight fighting in eastern Ukraine and urged Kiev to cease fighting and ensure dialogue with the rebels.
"Unfortunately, what we are seeing ... tells us that the fighting is ongoing and last night we saw some active use of artillery from the Ukrainian side," Mr Putin told the Rossiya-24 television channel.
"We need to ensure that all fighting is stopped."
He praised the call for ceasefire by Ukrainian President Petro Poroshenko, but said peaceful dialogue between Kiev and residents of Eastern Ukraine should begin.
Mr Putin told his German and French counterparts the Ukraine peace plan should be "backed up" with a de-facto ceasefire, the Kremlin said in a statement.
"Putin backed the decision by PA Poroshenko to carry out a peace plan," the read out of the phone conversation read. "... It was stressed that the intentions voiced by the head of the Ukrainian state should be backed up with a real ceasefire."
The Ukrainian forces seven-day ceasefire began last Friday as part of a peace plan by President Petro Poroshenko, but fighting continued throughout the weekend.