The antiviral is approved for treatment of smallpox, but can also be used for monkeypox under the US FDA's Expanded Access protocol.
The White House said that the 50K courses -- nearly five times more than the confirmed number of monkeypox cases in the US -- are being released so they can be prepositioned for easier patient access to the medication.
Allocation will be based 75% on the number of cases in a jurisdiction and 25% on the number of individuals who are at the highest risk of contracting the virus.