on the approval or authority of the Secretary of Defense, and payments may be made on his certificate of necessity for confidential military purposes: Provided further , That of the funds provided under this heading, not less than $48,000,000 shall be made available for the Procurement Technical Assistance Cooperative Agreement Program, of which not less than $4,500,000 shall be available for centers defined in 10 U.S.C. 2411(1)(D) : Provided further , That none of the funds appropriated or otherwise made available by this Act may be used to plan or implement the consolidation of a budget or appropriations liaison office of the Office of the Secretary of Defense, the office of the Secretary of a military department, or the service headquarters of one of the Armed Forces into a legislative affairs or legislative liaison office: Provided further , That $17,732,000, to remain available until expended, is available only for expenses relating to certain classified activities, and may be transferred as necessary by the Secretary of Defense to operation and maintenance appropriations or research, development, test and evaluation appropriations, to be merged with and to be available for the same time period as the appropriations to which transferred: Provided further , That any ceiling on the investment item unit cost of items that may be purchased with operation and maintenance funds shall not apply to the funds described in the preceding proviso: Provided further , That of the funds provided under this heading, $659,225,000 (reduced by $5,000,000) (increased by $5,000,000), of which $164,806,000 to remain available until September 30, 2022, shall be available to provide support and assistance to foreign security forces or other groups or individuals to conduct, support or facilitate counterterrorism, crisis response, or other Department of Defense security cooperation programs