Crimea's Tatars complain of crackdown by Russian occupiers:
The Ukrainian president's call "raises suspicions that he wants to destroy the Minsk accords", Mr Churkin said.
The Minsk ceasefire deal was reached a week ago but fighting round the strategic city of Debaltseve saw the withdrawal of Ukrainian troops there.
Russian-backed rebels in eastern Ukraine also criticised the proposal.
Mr Churkin accused Ukrainian President Petro Poroshenko of seeking a new scheme instead of doing what he had signed up to.
"If one proposes new schemes right away, the question arises whether [the accords] will be respected", he said.
The leadership of the self-proclaimed Donetsk People's Republic described the call for peacekeepers as a violation of the Minsk accords and asked the other parties to the deal - Moscow, Berlin and Paris - to influence Kiev.
The latest flaunting of the Geneva Conventions in eastern Ukraine:
Here is today's map of the security situation in eastern Ukraine, according to the National Security and Defense Council:
