Ukraine's foreign minister says a planned pullback of forces in the rebel east has been delayed because of recent skirmishes.
Ukraine and Russia-backed separatist rebels have agreed to pull their forces from the front line in two areas starting Monday to create a safe buffer zone.
But Foreign Minister Vadim Pristaiko says the move has been postponed due to recent shelling by separatists.
More than 13,000 people have been killed in the five-year conflict between Ukrainian troops and Russia-backed rebels.