Ukraine must decide what conditions are acceptable for negotiations to end the war, NATO Secretary General Jens Stoltenberg said, adding that NATO's role is to support Kyiv.

It is up to Ukraine to decide what conditions are acceptable, he said during a press conference with members of the Dutch government in The Hague.

Russia still control mosts of Ukraine, he said adding that the Russian Armed Forces retain significant capabilities as well as large numbers of troops.

The coming months are going to be difficult. Putin's goal is to leave Ukraine in the cold and dark this winter, Stoltenberg said, adding that the current conflict also shows the importance of diversifying our energy resources and protecting our critical infrastructure.