The Americans, because they are not a party to the law of the sea convention, are working slightly differently. They also have multiple areas around the world, of which the Arctic is only one. The U.S. has clearly been doing scientific work in the Arctic. Interestingly and notably, a lot of that research work has been done in cooperation with Canada. There are cooperation agreements between the two governments regarding a number of the scientific expeditions that have taken place in the high Arctic.
There are great photos of the American vessel breaking the ice and the Canadian vessel doing all the heavy lifting in the middle of the Arctic Ocean. It's an interesting example of the cooperation between our two countries.