Ukraine and Russia have accused each other of violating a 30-hour truce, but it comes as diplomatic efforts pick up, Russia Editor Steve Rosenberg writes.

Russian President Vladimir Putin declared a brief Easter ceasefire in his war with Ukraine, a declaration met with skepticism in Kyiv as the war enters a crucial phase and US-led negotiations stall.

Russia launched aerial attacks on Ukraine in a sudden end to the Easter truce as Putin questioned Kyiv's offer of a month-long halt to civilian targets.