The latest satellite images released by Maxar Technologies indicate Russian forces are moving from western Russia to eastern Ukraine. The US firm says the military is likely preparing for a new offensive in the Donbas region.

Maxar says images taken on Monday show military vehicles, tents and other items along a highway heading to the Ukrainian border from Soloti in Russia's Belgorod region.

The firm also says it also confirmed a convoy of dozens of Russian military vehicles was traveling on a highway near Vilkhuvatka in the eastern Ukrainian region of Kharkiv on Tuesday.

The firm says there are tanks among the vehicles.