The USA, as well as the USSR, initiated the convocation of the III UN Conference on the Law of the Sea (1973—1982). However, after the Ronald Reagan administration came to the White House, American diplomacy significantly changed its policy toward the Conference, which eventually resulted in US refusal to support the draft Convention on the Law of the Sea, which was worked out during the Conference. This behavior was in line with policy course of the Reagan administration — more aggressive than that of their predecessors. The article considers the American policy regarding Law of the Sea negotiations in the first months of Reagan's presidency, during the Tenth Session of the III UNCLOS.