The "Defending American Property Abroad Act of 2026" amends title 46, United States Code, to establish new conditions for vessels entering or operating in U.S. navigable waters and ports. This legislation aims to protect U.S. property interests in Western Hemisphere countries by creating a mechanism to restrict maritime traffic. It seeks to deter foreign governments from nationalizing or expropriating U.S.-owned assets by imposing consequences on vessels utilizing affected ports. Specifically, the bill empowers the President to designate foreign ports if a Western Hemisphere country, with which the U.S. has a free trade agreement, has nationalized or expropriated a port or its exclusive access land owned by a U.S. person. Vessels that have transited such a designated port may then be prohibited from entering U.S. ports or waters, though exceptions exist for vessels experiencing an emergency or those authorized by the U.S. property owner. The President must remove a port's designation if the foreign country returns the property, provides adequate and effective compensation, or otherwise resolves the dispute to the President's satisfaction, ensuring a pathway for resolution and the lifting of restrictions.