Prime Minister Yoshihide Suga and his Vietnamese counterpart Nguyen Xuan Phuc on Monday agreed to cooperate on regional issues including the South China Sea, where China's growing assertiveness in disputed waters has drawn concern from neighbors.

Speaking to reporters after summit talks with Phuc in Hanoi, Suga called Vietnam a "cornerstone" of efforts to realize a free and open Indo-Pacific and vowed Japan's continued contribution to "peace and prosperity in the region."

Suga, who is on his first overseas trip since taking office, said the countries had agreed in principle on a military pact that would enable Japan to export defense equipment and technology to Vietnam, including patrol planes and radar.