Junior defence minister James Heappey on Saturday while speaking to Sky News said British nationals who choose to stay in Ukraine should not expect a military evacuation if conflict with Russia breaks out.

"British nationals should leave Ukraine immediately by any means possible and they should not expect, as they saw in the summer with Afghanistan, that there would be any possibility of a military evacuation," he said.

On Friday the UK government advised British nationals to leave Ukraine while commercial means were still available and advised against all further travel to the country.

Britain is, however, maintaining a diplomatic presence in Ukraine.

British Defence Secretary Ben Wallace said on Friday British troops sent to Ukraine for training purposes would return soon.

(With input from agencies)