This bill, titled the "Defending American Property Abroad Act of 2025," seeks to protect the assets of United States persons from nationalization or expropriation by certain foreign governments. It establishes a mechanism to identify and impose restrictions related to specific foreign properties where such actions have occurred. The legislation defines "prohibited property" as any port, harbor, or marine terminal located in a covered foreign trade partner (a Western Hemisphere country with a U.S. free trade agreement) if it is accessible only through land owned by a U.S. person that has been nationalized, expropriated, or had contracts repudiated by the foreign government since January 1, 2024. The Secretary of Homeland Security, in consultation with the Secretaries of Treasury and State, must identify and designate all such prohibited properties within 60 days of the bill's enactment and publish this list. Once property is designated as prohibited, the President must implement strict prohibitions on vessels that have loaded at or previously used these locations. These prohibitions include preventing such vessels from importing or releasing goods into the United States, docking passenger vessels, releasing passengers, or receiving any servicing or maintenance activities in U.S. ports. Furthermore, the bill amends Section 301 of the Trade Act of 1974 to broaden the definition of "unreasonable or discriminatory" foreign acts, policies, and practices. This expansion now explicitly includes direct or indirect expropriation or nationalization of a United States person's assets, arbitrary or capricious treatment, denial of due process, or discrimination based on nationality concerning those assets. This change allows the U.S. to take retaliatory trade measures against countries engaging in such practices.