Yeah the Russians are saying that now cause they know they can't take all of Ukraine, but Putin and people around him said numerous times that Ukraine is part of Russia. Besides, Russia started this war by invading Kyiv and trying to tople zelensky to replace him with one of theirs, so yes, Ukraine is fighting for its right to exist.
They are not fighting for their right to exist as a country that doesn’t make any sense Russia made it clear what it takes to have a permanent ceasefire. The only ones who want time to rebuild their army are the ones clearly losing. https://primal.net/e/nevent1qqsxq2t74qmuzfr6uwgqcm63xz82qdyxjcna32yhsjdysevh8qslncgxg3fd2