MOSCOW, July 2 - Russia expressed "deep concern" on Thursday over Ukraine's plans to decentralize power as part of a peace deal with separatist rebels, underlining the gulf between Moscow and Kiev as the conflict rumbles on despite a ceasefire, Reuters reported.

Differing interpretations of a February peace agreement signed in Minsk, Belarus, to end the fighting in Ukraine's eastern regions have left the conflict in limbo, with more than 6,500 people killed since it broke out in April last year.