KYIV, Feb 25 (Reuters) - Ukrainian President Volodymyr Zelenskiy said on Friday that continued Russian aggression against his country showed that sanctions imposed on Moscow by the West were not enough.

Zelenskiy said the world was continuing to observe what was going on in Ukraine after its capital Kyiv and other parts of the countrywere struck by Russian missiles in the early hours of Friday.

Addressing the Russian population in Russian at the end of a televised speech, Zelenskiy said the bombing of Kyiv was reminiscent of Nazi Germany's attacks during World War Two.

"This is reminiscent of 1941," Zelenskiy said.

"To all the citizens of the Russian Federation who went out to protest, I want to say: we see you. This means you heard us. This means you are starting to believe us. Fight for us, fight against the war."

Hundreds were detained across Russian cities on Thursday after taking part in protests after Moscow launched a massive military operation against Ukraine.

A senior Ukrainian official said Russian forces would enter areas just outside Kyiv later on Friday.