I suspect Putin hopes that Ukraine will be more willing to compromise, if he keeps the pressure high, and Zelenskyy has no hope of aid from USA when Trump takes over.
But I think Zelenskyy knows or suspects that Russia is just as hard pressed internally as Ukraine is now, if not more.
But Iran may slow down sending more material to Russia, because now Israel is much more likely to attack them, because Trump will very likely give the green light when he becomes president.