Putin is lying, as usual.
without Biden in office, the invasion of Ukraine would not have occurred. And with Biden gone, Putin would be facing a more dangerous opponent to Putin’s invasion, if that foe were to be Trump.
No doubt, Putin is working behind the scenes to make sure Biden wins again, but mostly to make sure Trump does not get back as president.
I think this signals his desire is to take the whole of Ukraine. As long as he is willing to keep warring neither Biden nor Trump can stop him short of directly involving NATO, which neither is likely to do. If he wanted to negotiate a peace that allowed him to stop fighting and keep what he has taken I would think he would want Trump in office. If Putin truly doesn’t care it means he is set on option A.