Russian Defence Ministry image of a Russian soldier fires a gun toward a Ukrainian position in the Russian-Ukrainian border area in the Kursk region.More than half of the North Korean troops sent to fight on Vladimir Putin’s behalf in Russia have been injured or killed, according to the UK.North Korea’s leader Kim Jong Un signed a mutual defence pact with the Russian president last year, meaning they would each send troops to the other if attacked by a third party.Ukrainian troops launched a surprise incursion across the Russian border last August, an act of retaliation years after Putin first invaded Ukraine.So North Korean soldiers were deployed to the Russian region of Kursk to fight alongside the Russians.But