Fear-monger.
He is only saying that an attack anywhere in the new Russian territories will be answered with a swift military strike to the attacking nation.
If Ukraine continues offensive operations in the 4 former oblasts, Russia will decapitate leadership in Kiev, likely with a barrage of Kalibr cruise missile strikes.
Russia will also treat the hostiles within Russian territory as terrorists. They will no longer enjoy protections of Geneva Convention during hostilities or as POWs.
Putin is putting the World on notice, especially the Western governments supporting fighting in the former Ukrainian oblasts, that the SMO is over.
The main question is whether Russia will recognize the entire territory of the former oblasts as Russian territory or whether new borders will be established. Russia must have already clarified this point. If it hasn't, it will be clarified by Putin tomorrow.
So stop with your fearpron "doomsday countdown" clownlike bullshit.