"As soon as the border is closed, we could immediately proclaim a fire cease. It is irresponsible to announce a fire cease with an open border, given the situation in Donetsk and Lunhansk," the president told a National Security and Defense Council meeting on Monday.
"I hope we will fully succeed in doing so," the president added.
The president said at the meeting that he hopes the military operation to secure eastern Ukraine's border will conclude by the end of the week.
Notable deaths of 2014 [PHOTOS]