This bill grants the Secretary of Homeland Security new authority to suspend the entry of specific inadmissible aliens at U.S. land or maritime borders. The Secretary may exercise this discretion when necessary to achieve operational control over the border, prohibiting entry in whole or in part for a determined period. This discretionary power aims to enhance border management and security. Furthermore, the bill mandates the Secretary of Homeland Security to prohibit the entry of these "covered aliens" under certain conditions. This mandatory suspension is triggered if the Secretary cannot adequately detain such aliens as required by existing law or place them in an appropriate alternative program. To ensure compliance with this mandatory provision, the bill allows a State's attorney general or other authorized State officer to bring a civil action against the Secretary in federal court. This action can seek injunctive relief if a violation of the mandatory suspension affects the State or its residents.