Australia

No need to fear, Americans, we are as always standing ready to be your imperial lapdog

I just posted this. Antimony is not extracted in any real significant numbers outside of Russia, South Africa, Bolvia, and China. China alone produces over 90% of it. Hunan province is the jackpot on the stuff. Bolivia is the second biggest producer at just under 5%. Russia and South Africa produce about 1-2%. That's it. Some countries have strategic stores of it and some have a small mine here or there that is used purely for themselves because it is all they have. The US has 0 antimony mines currently. The US could waive environmental concerns and heavily subsidize a mine or two but it won't meet the needs of the military to produce the munitions which require it, like artillery shells.

Gallium in Ukraine/Russia, Slovakia as well as the UK lol, and Germanium in Russia and Northumberland

Whoever named these needs to check a map next time!

In other words, the US can still get those materials via their colonies in europe and australia.