; and (C) to implement other border security provisions under this section; (2) implementing port of entry provisions under this section; (3) purchasing new aircraft, vessels, spare parts, and equipment to operate and maintain such craft; and (4) hiring and recruitment. (b) Funding There are appropriated, to the Fund, out of any monies in the Treasury not otherwise appropriated, a total of $7,639,000,000, as follows: (1) For fiscal year 2018, $2,947,000,000, to remain available through fiscal year 2022. (2) For fiscal year 2019, $2,225,000,000, to remain available through fiscal year 2023. (3) For fiscal year 2020, $2,467,000,000, to remain available through fiscal year 2024. (c) Physical barriers (1) In general In each of the following fiscal years, the Secretary of Homeland Security shall transfer, from the Fund to the U.S. Customs and Border Protection—Procurement, Construction and Improvements account, for the purpose of constructing, replacing, or planning physical barriers along the United States land border, a total of $5,013,000,000, as follows: (A) For fiscal year 2018, $1,571,000,000. (B) For fiscal year 2019, $1,600,000,000. (C) For fiscal year 2020, $1,842,000,000. (2) Availability of funds Notwithstanding section 1552(a) of title 31, United States Code, any amounts obligated for the purposes described in paragraph (1) shall remain available for disbursement until expended. (d) Transfer authority Other than the amounts transferred by the Secretary of Homeland Security and the Secretary of State pursuant to subsections (b) and (c), the Committee on Appropriations of the Senate and the Committee on Appropriations of the House of Representatives may provide for the transfer of amounts in the Fund for each fiscal year to eligible activities under this section, including— (1) for the purpose of constructing, replacing, or planning for physical barriers along the United States land border