The United States is deploying the best military personnel and assets in the Asia-Pacific region under President Barack Obama's "rebalance to Asia" policy, Defense Secretary Ash Carter said Tuesday.

Carter also said in an article contributed to Foreign Affairs magazine that the Asia-Pacific security networks, including one involving the US, South Korea, and Japan, help ensure stability in the region amid a number of security challenges, including North Korea.

"In the rebalance's second phase ... the Pentagon is continuing to place some of our best military personnel in the region and deploying some of our most advanced capabilities there. Those capabilities include F-22 and F-35 stealth fighter jets, P-8A Poseidon maritime patrol aircraft, V-22 Ospreys, B-2 bombers, and our newest surface warfare ships," Carter said.

The Pentagon is also devoting resources to new capabilities critical to the rebalance, he said, adding that the US is increasing the number of surface ships and making each of them more lethal, while investing in Virginia-class submarines, advanced undersea drones, the new B-21 long-range strike bomber, and state-of-the-art tools for cyberspace, electronic warfare, and space.

Under the rebalance policy, the alliance between the US and South Korea "took a major step forward" in 2014 with an agreement to a conditions-based, rather than timeline-based, approach to determining when South Korea would obtain operational control of alliance forces in the event of a war, Carter said.

In July this year, the two allies also decided to deploy the THAAD missile defense system in South Korea at the earliest possible date as part of an effort to defend against North Korean ballistic missiles, he said.

Carter also noted strides in efforts to forge stronger trilateral security cooperation with South Korea and Japan.

"The US-Japanese-South Korean partnership helps coordinate responses to North Korea's nuclear and missile provocations, and earlier this year, the trio conducted its first-ever trilateral ballistic missile warning exercise," he said.

Such Asia-Pacific security networks will help ensure stability amid a number of security challenges, including North Korea's provocative behavior, he said. (Yonhap)