A decision made by Japan and the Philippines late last month to begin talks to delimit a maritime boundary between the two countries represents a ¡°big step¡± forward, said Makoto Seta, an expert on the law of the sea and professor at Japan¡¯s Waseda University.

China¡¯s criticism that such talks are illegal was based on flimsy legal grounds in terms of international law, Seta said in an interview.

The U.N. Convention on the Law of the Sea, or UNCLOS, recognizes each country has an exclusive economic zone of 200 nautical miles from its coasts.