MOSCOW, May 21 (Reuters) - The Kremlin said on Tuesday that Ukrainian President Volodymyr Zelenskiy was seeking greater Western involvement in the conflict because Ukrainian forces were in an extremely unfavourable situation at the frontline.

Zelenskiy

told Reuters

on Monday that he was pushing Western partners to get more directly involved in the war by helping to intercept Russian missiles over Ukraine and allowing Kyiv to use Western weapons against enemy military equipment amassing near the border.

Asked about the Reuters interview, Kremlin Spokesman Dmitry Peskov said some Ukrainian officials including Zelenskiy had been sometimes "slipping into hysteria" over recent days.

"This is due to the extremely unfavourable position of the forces of the Kyiv regime at the front," Peskov told reporters.

Peskov added that even if the flow of Western military aid increased then it would not change the big picture trend at the front, where Russian forces are advancing, and criticised Ukraine for shelling civilian areas in Russia.

President Vladimir Putin said on Friday that Russian forces advancing in Ukraine's northeast were carving out a

buffer zone

to protect Russia from attacks and said the West was "sick in the head" if it thought it could dictate terms to Moscow.

Russian forces control 18% of Ukrainian territory. (Reporting by Dmitry Antonov; editing by Guy Faulconbridge)