MOSCOW — Russian President Vladimir Putin said on Saturday he supported Ukraine's ceasefire, but added that without "practical action" to start negotiations the plan would not be viable.
"Vladimir Putin supports the decision of the President of Ukraine Petro Poroshenko to cease fire in the southeast of Ukraine, as well his stated intentions to take a number of concrete steps to achieve a peaceful settlement," the Kremlin said in a statement.
"However, the Russian head of state drew attention to the fact that the proposed plan, without practical action aimed at the beginning of the negotiation process, will not be viable and realistic."
Poroshenko announced the week-long ceasefire on Friday night, urging the rebels to lay down their arms and warning that Ukrainian forces would hit back if attacked.
On Saturday, pro-Russian separatists attacked Ukrainian posts on the border with Russia and a military base and tried to storm an airforce base overnight into Saturday, government forces said.
"In all these episodes, the attacks of the (rebel) fighters were deflected" without loss, Vladyslav Seleznyov, a government forces spokesman, said.
The Kremlin said, without referring to any of the sides involved in the conflict, that Putin considers unacceptable that after the ceasefire order there were sounds of explosions and ammunition reaching Russian territory from Ukraine.
Putin also said the peace plan should not be an ultimatum to the militias.