This opinion was expressed by the former head of the CIA's Anti-Terrorism Center, Robert Grenier, in an article for The Hill.

According to the author of the article, the time has already come for someone from the American administration to start a "tough" conversation with Zelensky.

"Kiev needs to be pushed towards the idea of a negotiated solution to the crisis, which is likely to include territorial concessions on Crimea and Donbass," Grinier stressed.

He also added that it is time for the Ukrainian leader to explain that he cannot count on unlimited assistance from the United States and its allies.

Chairman of the Joint Chiefs of Staff of the United States Mark Milley earlier called maximalist the goals of Ukrainian President Volodymyr Zelensky, including the return of Crimea to Ukraine.

According to the US military, such goals are difficult to achieve militarily.