Ukrainian soldiers on the battlefield expressed little hope for a diplomatic solution to the war with Russia, as US President Donald Trump's Friday deadline for the Kremlin to stop the killing arrived and he eyed a possible summit meeting with Russian President Vladimir Putin to discuss the conflict.

Trump's efforts to pressure Putin have so far delivered no progress. Russia's bigger army is slowly advancing deeper into Ukraine at great cost in troops and armour while it relentlessly bombards Ukrainian cities. Russia and Ukraine are far apart on their terms for peace.

Ukrainian forces are locked in intense battles along the 1,000-kilometre front line that snakes from northeast to southeast Ukraine. The Pokrovsk city area of the eastern Donetsk region is taking the brunt of punishment as Russia looks to break out from there into the neighbouring Dnipropetrovsk region.