Vietnamese President Tran Dai Quang and Japanese Prime Minister Shinzo Abe agreed during talks in Tokyo to strengthen defense cooperation in areas including military training, equipment and technology.
Quang is in Japan on a state visit marking the 45th anniversary of the countries' diplomatic ties.
In a statement after their talks, they called for a non-militarization of the South China Sea and warned against any unilateral actions changing the status quo.
Vietnam is especially concerned about Chinese efforts to establish sovereignty over islands that both countries claim. Abe has also been pushing for a ``free and open Indo-Pacific strategy'' of promoting peace, stability, prosperity and cooperation in the region amid China's increasing maritime influence.
The two leaders also agreed to strengthen cooperation in economy, trade and energy, and stressed the importance of a free and open multilateral trading system in line with World Trade Organization rules _ a policy that Japan has emphasized in recent trade disputes with the United States.
Quang was welcomed Wednesday at a state banquet hosted by Emperor Akihito, who is abdicating next April. He is in Japan until Saturday. (AP)