North Korean forces are “highly likely” to be fighting with their Russian counterparts in Ukraine, South Korea’s defense minister told lawmakers Tuesday in Seoul.

South Korean defense minister says casualties can be expected among Kim Jong Un's forces sent to fight in the war against Russia's neighbor.

South Korea’s defense minister on Tuesday said North Korea is strongly considering deploying its own troops to fight alongside Russia in Ukraine, amid reports that there have already been North Korean casualties in the war.

The US and its allies backing Ukraine have accused North Korea of sending weapons and munitions to Russia for use in its war.

North Korean soldiers are likely fighting in Ukraine alongside Russian troops, with some believed already killed and more expected to be deployed, Seoul's defence minister said Tuesday.

"As Russia and North Korea have signed a mutual treaty akin to a military alliance, the possibility of such a deployment is highly likely," South Korean Defense Minister Kim Yong-Hyun said in the parliament.

North Korean soldiers have probably been killed fighting for the Kremlin on the front lines in Ukraine, South Korea has said.

North Korea is reportedly sending troops to fight in Ukraine, according to South Korea’s defense minister, who addressed the parliament following reports that Pyongyang had suffered casualties on the battlefield.