To provide for the renewed availability of funds to construct the border wall upon the deployment of the National Guard to the southern land border of the United States, and for other purposes.

HR 1531 requires the Department of Homeland Security to immediately resume construction of physical barriers, roads, and border security technology along the U.S.-Mexico border whenever the National Guard is deployed there. It mandates using existing funds from fiscal years 2016-2022 for this purpose, prohibits canceling pre-January 2021 contracts, and requires honoring written agreements with states, tribes, or local governments. The bill specifies that barrier designs must use proven, operationally effective methods (like steel bollards) that prioritize agent safety and minimize community/environmental impacts. It applies directly to DHS, contractors, and local jurisdictions involved in border infrastructure projects.