Russia has said Kiev is stepping up a "blockade" of eastern Ukrainian regions controlled by pro-Russian rebels and accused Kiev of violating cease-fire agreements.
Ukrainian President Petro Poroshenko said during a visit to Berlin he wanted European Union leaders to make clear they would impose further economic sanctions against Russia if Moscow did not implement a cease-fire agreed in Minsk in February.
But Russia insisted it was Ukraine that was fomenting tensions by increasing human suffering.
"Kiev is not only sustaining but even enhancing the blockade of the Donbass region, severely limiting citizens'… communication with the rest of Ukraine, as well as their trans-border connections with Russian … regions," the Russian Foreign Ministry said in a statement.
Kiev has also halted gas and other supplies to the rebel east, much of which is beyond their control.
The Russian Foreign Ministry called that a direct violation of the Minsk agreements concluded by Russia, Ukraine, Germany and France in an effort to end almost a year of fighting in the Donetsk and Luhansk regions that embrace the industrial area known as the Donbass.
Both sides in the conflict, in which more than 6,000 people have died since April, have accused each another of violating the truce.
The Kiev government and its Western supporters accuse Moscow of deliberately driving the rebellion in eastern Ukraine by providing the rebels with arms and money and sending serving Russian troops across the border. Moscow denies direct military participation in the conflict.