Leaders of Japan and Vietnam have agreed to bolster cooperation in maritime safety and defense as they expressed shared concern over China’s growing activity in the South China Sea.

Vietnamese President Tran Dai Quang (CHAN DIE KWANG) and Japanese Prime Minister Shinzo Abe agreed Thursday to strengthen defense cooperation in areas including military training, equipment and technology.

In a statement after their talks, the two called for non-militarization in 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.

The two leaders also agreed to strengthen cooperation in the economy, trade and energy.

Quang is in Japan for a state visit marking the 45th anniversary of the countries’ diplomatic ties.