Despite U.S. non-party status to UNCLOS, all three branches of government have already accepted it as law of the land

Yet despite its problems, over the course of the years the Convention has gained support from the legislative, executive, and judicial branches of the U.S. Government. Indeed, UNCLOS has served as "the cornerstone of U.S. oceans policy since 1983."ⁿ³¹⁴ In 1980, anticipating both the mass appeal of UNCLOS and the potential conflict with American interests, Congress passed the Deep Seabed Hard Mineral Resources Act ⁿ³¹⁵ in order to establish a provisional regime that advanced the interests of the mining industry.ⁿ³¹⁶ The Act is still in force, having been reauthorized by Congress in 1986, four years after UNCLOS was available for signing.ⁿ³¹⁷

Even after refusing to sign the Convention, Reagan issued an Ocean Policy Statement in 1983 announcing that the United States "accepted, and would act in accordance with, the Convention's balance of interests relating to traditional uses of the oceans everything but deep seabed mining." ⁿ³¹⁸ In an executive order several years later, Reagan further elaborated that the United States would maintain a territorial sea of twelve nautical miles in compliance with UNCLOS, and that negotiations would remain open to develop a deep seabed mining regime.ⁿ³¹⁹ Faced with an obstinate Senate that refused UNCLOS in 1994, after the amended Convention was submitted for ratification, President Clinton issued a similar proclamation recognizing a contiguous zone consistent with UNCLOS in 1999.ⁿ³²⁰

Finally, U.S. domestic case law also reflects an intention to refrain from action that would be antithetical to the purposes of UNCLOS.ⁿ³²¹ Indeed, many federal court cases consider and apply provisions of the Convention, considering it an expression of customary international law at minimum.