Ukraine shocked the world with its bold offensive operation in the summer that at its height took control of an area about the size of Los Angeles in Kursk, Russia.

Ukrainian leader Volodymyr Zelensky denied Saturday his troops were encircled in Russia's Kursk region, where Moscow has regained swathes of land this week, as Russia said it took back two more villages in the border region.

Ukrainian troops are still fending off Russian and North Korean forces in the Kursk region but face a potential new attack on Ukraine's northeast Sumy region, President Volodymyr Zelenskiy said on Saturday.