The capability to go to space is the capability to rain tungsten rods down upon the earth.
Only Russia has enough tungsten to make that plan work, and if they stop exporting it, we cannot even make mil small arms bullets.
Looks to me like it’s China: https://www.indexmundi.com/minerals/?product=tungsten&graph=production But I could be wrong.
China is actually the big fish at 79 million Mt per year.
As to reserves on the North American continent, Bishop area of California, Nahanni area of western Northwest Territories, Canada. Drakelands Mine(Hemerdon) has a resource estimate of over 318 thousand metric ton of tungsten. Throw in Spain, Vietnam, and Rwanda for measure.
Market appears saturated with cheap Tungsten at the moment. Could stockpile ingot now at less than $11USD pound. Works out to $250,000 per large RFG in raw material.
At 18km.sec impact velocity and 11 metric ton, could yield .43 kiloton equivalent directed in a narrow shock-cone rather than omnidirectional. Control through plasma MHD is key to retaining more energy than simple ballistic re-entry.