Russia has supplied air defence missiles to North Korea in exchange for sending its troops to support Russia's war efforts against Ukraine, a top South Korean official said Friday. The US, South Korea and Ukraine say North Korea sent more than 10,000 troops to Russia in October, some of whom have recently began engaging in combat. It has been unclear what Russia would give North Korea in return. Shin Wonsik, national security adviser for President Yoon Suk Yeol, told a SBS TV program Friday that South Korea has found Russia provided missiles and other equipment to reinforce its air defence network for Pyongyang, the capital. Many observers say North Korea likely feels the urgent need to boost its air defence capabilities for the capital after the North last month accused South Korea of dropping propaganda leaflets over Pyongyang. North Korea threatened to take military action if leaflets were again dropped. South Korea's military has refused to confirm whether or not it was behind t