This illegal military cooperation between Russia and North Korea is a significant security threat to the international community and can pose a serious risk to our national security, says the president.
North Korea is sending around 10,000 soldiers to Russia to fight against Ukraine, announced the US Defense Department on Monday.
According to NATO, several of them are already in place in the Russian border region of Kursk, where Ukraine launched an offensive in August.
We must carefully investigate all possibilities and prepare countermeasures, says Yoon now.
On Tuesday, North Korea's Foreign Minister arrived in Russia, reports Russian state news agencies.
Earlier this summer, Russia's President Vladimir Putin visited North Korea and signed a partnership agreement with the closed country's dictator Kim Jong-Un. Among other things, the agreement stipulates that if either party is attacked or goes to war, the other will provide military assistance "in all possible ways".
North Korea has previously delivered significant quantities of weapons to Russia, including grenades and robots.
