ISTANBUL

Russia's former President Dmitry Medvedev on Wednesday said the UK is Moscow's "eternal enemy" and its officials who facilitate the war in Ukraine are "legitimate" military targets.

"The UK acts as Ukraine's ally providing it with military aid in the form of equipment and specialists, i.e., de facto is leading an undeclared war against Russia," Medvedev, who heads the Russian Security Council, said on Twitter.

"That being the case, any of its public officials (either military, or civil, who facilitate the war) can be considered as a legitimate military target."

His comments came a day after UK Foreign Secretary James Cleverly said Ukraine had the right to “project force beyond its borders” for self-defense.

Medvedev, who also served as Russia's prime minister, said: “The goofy officials of the UK, our eternal enemy, should remember that within the framework of the universally accepted international law which regulates modern warfare, including the Hague and Geneva Conventions with their additional protocols, their state can also be qualified as being at war."

The UK has been a staunch Ukraine ally since the war began in February last year. It is providing economic, humanitarian and defensive military assistance to Kyiv, and also imposing sanctions on Russia.