NATO Secretary-General Mark Rutte kicked off a two-day trip to Japan on Tuesday with visits to Yokosuka Naval Base and Mitsubishi Electric Kamakura Works in Kanagawa Prefecture ¡ª a move that highlights the military alliance¡¯s push to expand its partnership with Tokyo, particularly in the field of military-industrial ties.

¡°China is building up its armed forces, including its navy, at a rapid pace, so we cannot be naive and we really have to work together to assess what is happening,¡± he said at the Yokosuka base.

One of the focal points of the visit, Rutte said, is to explore ways to ramp up cooperation with the alliance¡¯s four Indo-Pacific partners (IP4): Japan, South Korea, Australia and New Zealand.