SEOUL — US Defense Secretary Lloyd Austin on Tuesday highlighted America’s “ironclad” and “unwavering” security commitment to South Korea, as some raise doubts about Washington’s “extended deterrence” commitment for the key ally amid evolving North Korean threats, Yonhap News Agency reported.

There would be more frequent deployments of such high-profile US strategic assets as advanced stealth jets and aircraft carriers to Korea, Austin was quoted as saying at a joint press conference with South Korean Defense Minister Lee Jong-sup following bilateral talks in Seoul.

“Our commitment to the defense of the ROK remains ironclad, and the US stands firm in its extended deterrence commitment,” he said, referring to South Korea by its official name, the Republic of Korea.

“That includes the full range of US defense capabilities, including our conventional, nuclear and missile defense capabilities. Now, we have 28,500 uniformed personnel in South Korea. This shows our unwavering commitment,” he added.

His remarks came after North Korean leader Kim Jong-un publicly called for an “exponential” increase in his country’s nuclear arsenal and named the South an “undoubted” enemy at a December ruling party meeting.

Austin’s trip comes as Seoul and Washington are striving to sharpen deterrence through reinforced combined military drills as well as their trilateral security coordination with Tokyo, in the wake of Pyongyang’s missile provocations.

Extended deterrence means the United States’ pledge to mobilize a full range of its military capabilities, including nuclear, to defend its ally.

Lee and Austin discussed ways to flesh out last year’s trilateral summit agreement by the leaders of South Korea, the US and Japan to share missile warning data “in real time” to help address North Korean threats.

Meanwhile, according to Seoul’s public broadcaster KBS, Austin and Lee agreed to continue and step up alliance capabilities, information sharing, joint planning, execution and consultations to deter North Korea’s missile and nuclear threats.

To this aim, the allies will hold a table-top exercise next month led by the Deterrence Strategy Committee and discuss a timely and coordinated deployment of strategic assets.

The two sides also agreed to expand the scale and scope of joint field maneuvers this year, including a major live fire drill. Seoul and Washington will also seek to hold trilateral security talks with Japan at the earliest possible date.

The Pentagon chief arrived here on Monday on a regional swing that will also take him to the Philippines. — Agencies