New Defense Minister Minoru Kihara said Sunday that he is “very concerned” about China’s rapid military buildup and moves in the East and South China seas, calling trilateral security cooperation between Japan, South Korea and the United States “the cornerstone” of Tokyo’s response to an increasingly tense regional environment that also includes North Korea and Russia.

Kihara, who replaced his predecessor, Yasukazu Hamada, in a Cabinet reshuffle Wednesday, highlighted the need for continuity as Japan continues to shed some of the postwar constraints on its military amid a number of growing threats.

“In the face of the most severe and complicated security environment since the end of World War II, I would like to maintain the direction of my predecessor to fundamentally strengthen our defense capabilities,” he told an NHK television program.