Subject to section 2343 of this title and subject to the availability of appropriations, the Secretary of Defense may—

(1) acquire from the Governments of North Atlantic Treaty Organization countries, from North Atlantic Treaty Organization subsidiary bodies, and from the United Nations Organization or any regional international organization logistic support, supplies, and services for elements of the armed forces deployed outside the United States; and

(2) acquire from any government not a member of the North Atlantic Treaty Organization logistic support, supplies, and services for elements of the armed forces deployed (or to be deployed) outside the United States if that country—

(A) has a defense alliance with the United States;

(B) permits the stationing of members of the armed forces in such country or the homeporting of naval vessels of the United States in such country;

(C) has agreed to preposition materiel of the United States in such country; or

(D) serves as the host country to military exercises which include elements of the armed forces or permits other military operations by the armed forces in such country.