Russian President Vladimir Putin and North Korean leader Kim Jong UnVLADIMIR SMIRNOV/POOL/AFP via Getty ImagesNorth Korea got a good deal by sending its officials to help Russia's Ukraine war, experts said.It doesn't just bring a payment lifeline — it gets access to vital combat data from a war zone.The partnership with Russia provides vital resources for North Korea's strained economy.The reported presence of North Korean officials aiding Russia's war in Ukraine is a "win-win" scenario for Kim Jong Un, offering military advantages with few downsides, experts on the reclusive territory told Business Insider.In a discussion on Monday, Ukrainian President Volodymyr Zelenskyy said: "North Korea has, in fact, entered the war," per state-run outlet United24 Media.It follows a Washington Post report that cited a Ukrainian military intelligence official as saying thousands of North Korean troops are already in Russia, receiving training for potential combat by the end of the year.