There are signs a last-minute land grab is taking place in Ukraine, as the deadline for a ceasefire moves nearer.

Almost 30 civilians and soldiers have been killed as separatists attempt to take more territory ahead of the truce.

It takes effect early Sunday New Zealand time, but even now Ukraine's president Petro Poroshenko has doubts.

"We are still a very long way from peace. Nobody has a strong belief that the peace conditions that were signed in Minsk will be implemented."

In Donetsk, CNN's Nick Paton-Walsh says it's unlikely the fighting will stop completely.

"With so much anger on the ground, so many disparate groups, such a visibly confused chain of command on the ground, that will add great complexity, and frankly so many sides here are waiting for any excuse to continue the fight."