; 136 Stat. 2492) is amended by adding at the end the following new paragraph: (4) Biennial updates (A) In general Not less frequently than once every two years after the submittal of the initial strategy under paragraph (1), the Secretary of Defense shall— (i) revise and update the strategy; and (ii) submit the revised and updated strategy to the appropriate congressional committees. (B) Sunset The requirement to prepare and submit updates under this paragraph shall terminate on December 31, 2030. . (b) Limitation on availability of funds pending submittal of strategy Of the funds authorized to be appropriated by this Act or otherwise made available for fiscal year 2024, and available for the Office of the Under Secretary of Defense for Research and Engineering for the travel of persons, not more than 90 percent may be obligated or expended until the date on which the Secretary of Defense submits to the congressional defense committees the strategy required under section 237(c)(1) of the National Defense Authorization Act for Fiscal Year 2023 ( Public Law 117–263