Russia and pro-Russian separatists in eastern Ukraine have criticized a Ukrainian draft law granting the rebel-held areas special status.
Denis Pushilin, a separatist leader in the Donetsk region, described the bill as "a crude violation" of the cease-fire deal reached in Minsk last month.
Russia said the bill raised "serious" concerns.
"The way things have developed shows that the Ukrainian leadership has chosen the course of rejecting key principles of the Minsk process," the Foreign Ministry said.
The text of the bill says rebel-held areas in Donetsk and Luhansk regions will be granted their special status after holding elections in accordance with Ukrainian law and under international observation.
It states that armed groups and weapons would also have to disarm or leave Ukraine.
Ukrainian parliament speaker Volodymyr Hroysman said lawmakers would vote in the coming week on the draft law.