I think the subtext might be that Biden is trying to pressure the ukraine president to not be allies with Ryussia, which 99% of the ukraine people want, and Biden's son had previously been involved in euromaiden which was a fake pro europe/USA thing in the Ukraine. But the polish president is not really afraid of Russia and knows they'd be better off being allies with them so basically said tone down the rhetoric. The ukraine president leaked this because when russia never invades it'll make biden look bad.