The defence cooperation deal signed by Russia and North Korea obligates both states to provide military assistance “without delay” in the case of an attack on the other. Russia’s President Vladimir Putin struck the deal during a visit to North Korea in June.

Russian President Vladimir Putin on Saturday signed a treaty on the country's strategic partnership with North Korea which includes a mutual defence provision, enacting it into law. The accord, announced by Putin and North Korean leader Kim Jong Un in June after a summit in Pyongyang,

Ukraine's top military commander, Oleksandr Syrskyi, said on Saturday that there were reports North Korean troops were preparing for combat alongside Russian forces. "We have numerous reports of North Korean soldiers preparing to participate in combat operations alongside Russian Forces,