(c)
The Postal Service may advance to an air carrier, out of funds available for payment of balances due other countries, the amounts determined by the Postal Service to be due from another country to an air carrier for the transportation of its mails when—
(1)
collections are to be made by the United States for the account of air carriers; and
(2)
the Postal Service determines that the balance of funds available is such that the advances may be made therefrom.
Collection from another country of the amount so advanced shall be made by offset, or otherwise, and the appropriation from which the advance is made shall be reimbursed by the collections made by the United States.