minsk substantial difference germany france envisage possible deployment u.n. peacekeepers eastern ukraine russia position german foreign minister sigmar gabriel tell journalists friday kiev moscow propose u.n. peacekeepers deploy help resolve ukraine pro-russian separatist conflict side disagree whether troop position rebel-controlled part ukraine-russia border germany france russia ukraine previously hold talk effort end fight kill 10,000 people despite notional ceasefire germany france idea russia idea blue helmets peacekeeping mission would shape still far apart gabriel say official visit belarus nevertheless gabriel say deployment would represent real chance peace war-torn donbass region although ideas still far apart would inadvisable close window opportunity say germany france disagree russia deploy peacekeepers ukraine gabriel