The incoming U.S. Pacific commander said Tuesday that North Korea is "our most volatile and dangerous threat" as it pursues nuclear weapons and long-range missiles, vowing to fight and defeat the communist nation if deterrence fails.

Adm. Harry Harris Jr. made the remarks during a Senate Armed Services Committee hearing to confirm his nomination as new chief of the U.S. Pacific Command (PACOM). Harris was named in September to succeed Adm. Samuel Locklear III as PACOM commander.

"If confirmed, I look forward to working closely with this committee as our nation confronts complex and compelling challenges in the vibrant Asia Pacific region," Harris said during the hearing. "Our most volatile and dangerous threat is North Korea with its quest for nuclear weapons and a means to deliver them intercontinentally."

In a written statement prepared for the hearing, Harris also said that the North's nuclear and missile programs "present a clear and present danger to regional security and stability." He also described those threats as "my greatest concern," "my No. 1 security concern" and an issue that "keeps me awake at night."

"Forward-based and forward-deployed U.S. military presence in the Western Pacific will continue to reassure our treaty allies and deter aggression by North Korea. If this fails, I will ensure Pacific Command forces are prepared to fight and defeat North Korean forces," Harris said in the statement.

Harris also expressed marked concern about the North's missile programs.

The North's Taepodong-2 long-range rocket could reach the U.S. if it is developed as an intercontinental ballistic missile.

Moreover, the North also developed a new road-mobile intercontinental ballistic missile, known as the "KN08."

"Though never flight tested, the KN08 could reach the continental U.S.," he said.

Harris also said he will work with allies to maintain peace on the Korean Peninsula and bring about the verifiable elimination of the North's nuclear weapons program and that the U.S. commitment to the security of South Korea is "unshakable."

The admiral said that the U.S. remains committed to maintaining current troop levels in South Korea. Before deploying any forces from South Korea to other places, the U.S. will carefully weigh the potential risk to regional security and stability with competing national security objectives, he said.

"We would not do anything that diminishes the alliance's capability to fulfill its objectives," he said.

The U.S. keeps about 28,500 troops in South Korea to deter North Korea.

North Korean leader Kim Jong-un's consolidation of power appears to have eliminated de-stabilizing factors inside the country in the near term, but his frequent reshuffling of senior leadership heightens U.S. concern as new variables have been added to the North's decision-making calculus, Harris said.

The admiral also said that Pyongyang's recent diplomatic and other efforts to reach out to the outside world underscore the North's strategy of simultaneously seeking economic development and nuclear weapons. 

Harris said he supports a recent decision between the U.S. and South Korea to postpone a planned transfer of wartime operational control of South Korean forces from Washington to Seoul until the South secures the capabilities to defend against the North.

He also stressed the importance of trilateral security cooperation between the U.S., South Korea and Japan. He urged Tokyo to increase its security cooperation with Seoul. 

"I remain concerned that the Japan-South Korea relationship is strained and exacerbated by historical animosities and territorial disputes. This is distracting to us and doesn't allow for the full realization of truly transformative defense architectures in East Asia," he said. "I worry that other powers may try to use this friction to drive a wedge between us and either ally." (Yonhap)