South Korea has recalled its ambassador to Ukraine, escalating a diplomatic spat that began last month when Kyiv disclosed it had transferred two captured North Korean soldiers to Seoul. South Korea accuses Ukraine of breaching a secrecy agreement regarding the transfer, a claim Ukraine denies. The North Korean soldiers had supported Russia in the Ukraine war and expressed a desire to be sent to South Korea. The incident has strained relations, with South Korea demanding an apology for what it calls a "falsehood" and Russia warning of retaliation if South Korea provides lethal weapons to Ukraine.