Ukraine war latest: Ukraine strikes 3 Russian air defense systems in single day; 3,800 North Korean troops killed, injured in Kursk Oblast
Key developments on Jan. 6: * Ukraine strikes 3 Russian air defense systems in single day, Navy claims * 3,800 North Korean troops killed or injured in Russia's Kursk Oblast, Zelensky says * Ukraine's position in Kursk Oblast important for possible negotiations, Blinken says * Zelensky offered to buy weapons from incoming Trump