Tusk made the remark in an interview with The Times.“I have no doubts Ukraine will survive as an independent state,” Tusk said. “Now the main question is how many victims we will see. President Zelensky told me [on Thursday] that he hopes that the war will not last ten years, but that Ukraine is ready to fight for another two, three years.”In addition, the Polish prime minister noted that Kyiv is concerned about the possible consequences of a prolonged war for the country's economy and population.At the same time, Tusk assessed that Russia is experiencing serious economic difficulties, but warned the West against excessive optimism.“The Russians are in really deep trouble [economically],” he stressed. "Does it mean we can say we are winning? Not at all. They have one big advantage against the West, and Europe especially: they are ready to fight … in wartime, this is absolutely the crucial question (...) You have no chance to win if you are not ready to fight or at least to sacrifice something."Earlier, the Institute for the Study of War warned that Russia, together with Belarus, could send special forces to carry out sabotage against Poland's critical infrastructure and then blame Ukraine for it.