North Korean leader Kim Jong-un, left, and Russian President Vladimir Putin hold a meeting at the Diaoyutai State Guest House in Beijing, Sept. 3. YonhapNorth Korean leader Kim Jong-un has pledged unwavering support for Moscow in a congratulatory letter to President Vladimir Putin marking Russia Day, Pyongyang's state media reported Friday.Kim extended his "warmest congratulations" to Russia on its national day, which commemorates the 1990 declaration of Russian state sovereignty, according to the Korean Central News Agency (KCNA).The two countries' relationship, Kim wrote, is being "further strengthened into sincere and devoted relations of comradely trust and alliance, opening a new chapter of history," the report said.He credited the growing bond to both sides honoring their obligations under the comprehensive strategic partnership treaty the two leaders signed at their Pyongyang summit in June 2024."It is the invariable will and stand of mine and the DPRK government to fully support the internal and external policies of Moscow and always join the Russian Federation," he added. DPRK stands for the Democratic People's Republic of Korea, North Korea's official name.The letter, dated June 12, was delivered by North Korea's Ambassador to Russia Sin Hong-chol in a meeting with a Russian foreign ministry official, the KCNA reported earlier.