Ukraine's President has promised greater autonomy to Eastern Ukraine while rejecting the possibility of federalization.
Petro Poroshenko says he will introduce a bill as early as next week that will offer greater autonomy to the largely Russian-speaking east.
He stresses that Eastern Ukraine will remain part of the Ukrainian state.
"The ceasefire deal provides Ukraine with sovereignty over the Donbas region, including the area which is under rebel control. This territory will come back within the territory of Ukrainian law. We would like to draw your attention to the fact that we do not mention any federalization or separation in the protocol."
Meanwhile, rebel fighters are still pushing for federalization, saying people in eastern Ukraine will not abide by Kiev government rule over their region.
Ukraine's military recorded at least six violations of the current ceasefire overnight but said there were no casualties.
The Kiev government says the ceasefire reached last week has proven effective.
Meanwhile, Ukraine's former Prime Minister Yulia Tymoshenko has called for a referendum on joining NATO.
The former Prime Minister presented documents to the Central Electoral Commission in Kiev asking for a nationwide referendum on NATO membership.
