Japan is helping Vietnam build a defense against the larger, more militarily powerful China as Vietnam says Beijing's forces are occupying more than their legal share of the South China Sea.
Japanese Defense Minister Takeshi Iwaya and his Vietnamese counterpart, Ngo Xuan Lich, met May 3 to "advance cooperation" on maritime security, Tokyo-based NHK television online said.
In October, the ministers met in Tokyo to discuss issues surrounding the South China Sea. They signed a "defense cooperation and exchange" memorandum that prescribed regular vice ministerial-level talks, the Japanese defense ministry website says.
Japan has been jousting with China over sovereignty in parts of the East China Sea, including a chain of uninhabited islets coveted by fishing fleets.
"Essentially there is an arc of anxiety stretching from New Delhi to Canberra and Jakarta and Hanoi and Tokyo," said Jeffrey Kingston, history instructor at Temple University, Japan Campus. "So, I think that perhaps the rhetoric is aimed at signaling that there are collective, shared concerns that are leading towards a collective response."