That "admiral" lied a lot. The trenches have little to do with defense. It's for infrastructure. Probably water lines to Crimea. As for taking Kyiv. The Russians did earlier and left after they destroyed the airport. This was done to make sure Zelensky couldn't launch from it into Belarus or Southern Russia. Since then the Russians have popped it several times with missile attacks. Putin doesn't want Kyiv but will nuke it should the situation call for it. Slava Russia, you fed fuckers!