You can find this in plenty of sources showing Putin’s speeches and interviews.
He’s quite a historian.
If neither side is willing to accept territory concessions to Russia, they’ll have to keep fighting and killing each other. Until one side runs out of soldiers.
You are ignoring the other demands of Putin. They would entail the end of Ukraine as a nation. Putin has repeatedly said that he will not accept a freeze in the current status. He wants more. He wants to bring Ukraine back under Moscow’s control. You can also find plenty of sources showing this.