Following the recapture of the city of Kherson, Ukraine faces difficult months ahead, NATO Secretary General Jens Stoltenberg said. Stoltenberg on Monday praised the “incredible courage” of Ukrainian forces following Russia’s withdrawal from the strategic capital in the southern region and urged continued international support for Kyiv. “The coming months will be difficult. [Russian President Vladimir] Putin’s aim is to leave Ukraine cold and dark this winter,” he told reporters in The Hague after meeting the Dutch foreign and defense ministers. “We must not make the mistake of underestimating Russia,” Stoltenberg said, stressing that Moscow’s forces “retain significant capabilities, as well as a large number of troops.” “Russia has shown a willingness to suffer significant casualties,” Stoltenberg added. The city of Kherson was the first major urban hub to fall to Russian forces after Russia’s February 24 invasion of Ukraine, and the only regional capital captured by Moscow’s troops. Russian forces withdrew last week after General Sergei Surovykin announced they could no longer supply the region. Moscow’s retreat “demonstrates the incredible courage of Ukraine’s armed forces, but it also demonstrated our continued support for Ukraine,” Stoltenberg said. The liberation of the city is the latest in a series of setbacks for the Kremlin after it was pushed back from large swaths of territory in the south and east. Ukrainian President Volodymyr Zelenskyy visited the newly liberated city on Monday after he said on Sunday that evidence revealed hundreds of new “war crimes” committed by the Russian occupiers. Stoltenberg said Russian forces “showed extreme brutality”. “You have all seen the horrific scenes from the liberated territories and the indiscriminate attacks on civilians and critical infrastructure,” Stoltenberg told reporters. Residents of the area celebrate after the retreat of Russia in the center of Kherson [Yevhenii Zavhorodnii/Reuters] It was not clear if he was referring to Kherson specifically. Stoltenberg also said it was now up to Ukraine to decide the terms of negotiations to end the war. Kremlin spokesman Dmitry Peskov declined to comment on Zelensky’s visit to Kherson, insisting: “This territory is part of the Russian Federation.” Stoltenberg met with Dutch Foreign Minister Wopke Hoekstra and Defense Minister Kajsa Ollongren to discuss the Netherlands’ contribution to NATO and the war in Ukraine. “We all see now, with the liberation of Kherson, that the Ukrainian strategy is working,” Olongen said. “But winter is coming… and we must stay the course. “If Russia stops fighting tomorrow, there is no more war. “If Ukraine stops fighting, there will be no more Ukraine,” he said.