Russia is using civilian-plated trucks to transport "mercenaries" from North Korea to a frontline area, Ukraine's military intelligence service has said, amid concerns over North Korean troops possibly joining combat in Russia's war on Ukraine.On Sunday, Russian police officers stopped a truck with civilian license plates carrying North Korean military personnel on the Kursk-Voronezh highway, the Defense Intelligence of Ukraine said, noting the driver did not have a combat order.The announcement comes amid reports of North Korean troops gathering in Russia's southwestern region of Kursk, where a major Ukrainian incursion took place in August.Last week, South Korea's spy agency said 3,000 North Koreans have been sent to Russia, with about 10,000 expected to be deployed by December. The United States has also confirmed at least 3,000 North Koreans have been sent to eastern Russia this month.South Korea has vowed to take "phased measures" in response to the level of military cooperation between North Kor ea and Russia, with President Yoon Suk Yeol saying Seoul could consider providing arms to Kyiv, in a possible shift from its policy of only sending humanitarian aid.Source: Yonhap News Agency