U.S. claims to a vast section of the seabed floor — and the potential resources buried within — have no basis in international law and should be rejected, according to government representatives from Russia and China.

The comments came during a debate at a session of the International Seabed Authority in Kingston, Jamaica, in response to recent claims by the U.S. that would add about 1 million square kilometers to its continental shelf in the Bering Sea, Pacific Ocean, Atlantic Ocean and Gulf of Mexico.

Countries that have ratified the 1982 United Nations Convention on the Law of the Sea undergo a lengthy international process to reach agreement on where the boundaries of underwater continental shelves lie.