North Korea's military upgrade / An open secret. Why Moscow and Pyongyang held off on acknowledging North Korean troops fighting against Ukraine / 'We will always honor the Korean heroes who gave their lives for Russia': Putin thanks Kim Jong Un for North Korea's help in battle for Kursk / North Korea purges 20 elite soldiers for 'threatening Kim Jong-un's life' by breaking simple rule during war drills / ISW: Russia sends military to North Korea potentially to share combat experience / North Korean soldiers in Russia told to take their own lives rather than surrender / North Korean troops told to choose suicide over capture in Ukraine: Seoul / Experts say it appears North Korean soldiers, fighting with Russia, are ill-prepared / Ukraine war briefing: North Korean troops yet to make major impact on fighting, says Ukraine military intelligence / Don't underestimate North Korean troops in Russia, ex-soldiers tell BBC