The United States and Japan need to maintain a strong security alliance to quickly respond to any threat in the Asia-Pacific region, the new commander of U.S. Forces Japan said Tuesday.

"Because of the clear threats to peace and security in this region, we must maintain the highest levels of readiness to respond at a moment's notice to any threat, any crisis or any humanitarian disaster," Lt. Gen. Kevin Schneider said at a ceremony held at Yokota Air Base in the suburbs of Tokyo.

Schneider succeeded Lt. Gen. Jerry Martinez, who during his tenure faced challenges such as North Korea's nuclear and missile development, as well as China's maritime assertiveness.