Pure fission is limited to about 500kt (this is a rough figure, if anyone has any actual data, I would appreciate a link....), and as has been previously stated the Tsar Bomba was the largest fusion bomb ever detonated at around 57 mt. Of course, it was massive, took up the entire bomb bay of a heavy bomber and was deployed via drogue parachute much like one of the “daisy cutter” bombs. Chelomei actually designed the UR-500 (aka Proton) as a massive ICBM to loft it state-wards... never deployed, obviously.
Interesting. I was not aware of a limit to fission bombs.
Oh well, maybe they’ll just drop several. With nukes, millimeter aiming precision isn’t exactly necessary.