British Defence Secretary Ben Wallace said on Thursday (April 28) it would be legitimate for Ukrainian forces to target Russian logistics but they were unlikely to use British weapons to do so.
Moscow has accused London of provoking Ukraine to strike targets in Russia, saying there would be an immediate "proportional response" if it continued.
Wallace told the BBC that Ukraine would be justified in targeting Russian military logistics targets under international law, but that long-range weapons were unlikely to be of British origin.
Ukrainian forces tend to use land-based mobile launchers to deploy long-range weapons, which is not something Britain has supplied Kyiv, Wallace said.