So, Russia and Ukraine are still as far apart as ever, with the two warring countries unable to make a significant breakthrough in direct talks in Istanbul.

Delegations from the warring sides met for barely an hour and agreed to exchange more prisoners of war - focusing on the youngest and most severely wounded - and return the bodies of 12,000 dead soldiers.

The second recent round of direct discussions, in Istanbul, resulted in an agreement to trade more prisoners, but produced few steps toward ending the fighting.