Russia battled on Sunday to drive the last Ukrainian soldiers from western Russia, Russian officials said, after a seven-month incursion by Ukraine that aimed to distract Moscow's forces, gain a bargaining chip and rile President Vladimir Putin.

At the height of the campaign, Ukrainian forces controlled some 500 square miles of Russian territory. Now they hold just a small sliver of land along the border.

LONDON/KYIV (Reuters) - Tens of thousands of Ukrainian troops who smashed into Russia last summer and took control of a swathe of territory there are nearly encircled by Russian forces and cut off from their main supply lines, open source maps showed on Friday.