Ukrainian, Russian, German and French leaders discussed the first day ceasefire in a four-sided telephone conversations France and Germany believe the ceasefire in Ukraine is "generally" being observed.But the countries" leaders, who helped broker the truce, said some "local incidents" must be "quickly" resolved.
Shelling has continued around the besieged town of Debaltseve.
However, fighting in the area is reported to have lowered in intensity since the ceasefire began at midnight Saturday
Pro-Russian rebels had previously said they were entitled to fire in the town, as they believe the territory belongs to them.
Meanwhile, a military spokesman said Ukrainian troops had come under fire 60 times in the hours after the truce came into force.The spokesman said Debaltsevo continued to be the scene of most clashes.
The situation in the east of Ukraine was to be discussed at the UN Security Council. However, the meeting was postponed. It is unknown when the United Nations will discuss this topic.