; and of which $172,000,000 is for additional Office of Field Operations staffing: Provided , That not to exceed $34,425 shall be for official reception and representation expenses: Provided further , That not to exceed $150,000 shall be available for payment for rental space in connection with preclearance operations: Provided further , That not to exceed $2,000,000 shall be for awards of compensation to informants, to be accounted for solely under the certificate of the Secretary of Homeland Security: Provided further , That not to exceed $5,000,000 may be transferred to the Bureau of Indian Affairs for the maintenance and repair of roads on Native American reservations used by the U.S. Border Patrol: Provided further , That, not to exceed $75,000,000 shall be transferred to the United States Fish and Wildlife Service for mitigation activities, including land acquisition, related to the construction of border barriers on Federal lands: Provided further , That of the funds made available under this heading for the Executive Leadership and Oversight program, project, and activity, $5,000,000 shall be withheld from obligation until the Commissioner of U.S. Customs and Border Protection submits the report required by section 209(b). procurement, construction, and improvements For necessary expenses of U.S. Customs and Border Protection for procurement, construction, and improvements, including procurement of marine vessels, aircraft, and unmanned aerial systems, $877,547,000, of which $750,148,000 shall remain available until September 30, 2023, and of which $127,399,000 shall remain available until September 30, 2025. U.S. immigration and customs enforcement operations and support (including transfer of funds) For necessary expenses of U.S. Immigration and Customs Enforcement for operations and support, including the purchase and lease of up to 3,790 (2,350 for replacement only) police-type vehicles; overseas vetted units