A senior U.S. official said Wednesday that the United States will send a nuclear submarine to stop in South Korea with the aim of boosting deterrence capabilities against North Korea.

The official said the measures to be announced had not been seen since the Cold War era and were aimed at enhancing deterrence capabilities against North Korea's nuclear activities.

The official noted that in addition to submarines, there would be a "usual flow" of other major platforms "including bombers or aircraft carriers," adding that "these means will certainly not be stationed (in the region), and certainly no nuclear weapons."

US President Joe Biden and his South Korean counterpart Yoon Suk-yeol, who is currently visiting the United States, are due to issue a document called the "Washington Declaration", which, in addition to strengthening the US military umbrella, will determine increased information sharing with Seoul.

The move comes in response to escalating tensions as North Korea has increased missile tests, with Pyongyang this year conducting a record number of tests, including this month testing the first solid-fuel ballistic missile.

Yoon and his wife will head to the White House on Wednesday for a visit that includes a gala dinner and other official events, coinciding with the seventieth anniversary of the U.S.-South Korea alliance.

Biden is seeking to strengthen cooperation with Washington's two most important regional allies against North Korea, South Korea and Japan.


Extended deterrence

A senior U.S. official said before Biden-Yun's meeting that "the United States has not actually taken such steps since the height of the Cold War with our closest allies in Europe," noting that Washington seeks through these measures to confirm its commitment to "expanded deterrence (and that) is beyond doubt."

Officials said on condition of anonymity that there were no plans to deploy U.S. nuclear weapons in South Korea, unlike in the Cold War when U.S. strategic weapons were deployed in Europe.

"We will announce our intention to take steps to make our deterrence more visible through the regular deployment of strategic assets, including the visit of the U.S. nuclear ballistic submarine to South Korea, something that has not happened since the eighties," a senior official said.

"We will enhance our exercises, exercises and simulation activities to enhance the U.S.-Republic of Korea alliance's approach to deterrence and defense against North Korean threats, including by integrating traditional South Korean assets with our strategic planning," he said.

One official noted that steps were already being taken to defuse any potential tensions with Beijing due to a tougher military posture.

"We keep the Chinese informed in advance and make it very clear why we are taking these steps," he said, adding that Joe Biden's administration was "betrayed that China was not willing to use its influence" over Pyongyang.

Officials in Seoul and Washington have been warning since early 2022 that North Korea could conduct its seventh nuclear test in the near future.

In March, leader Kim Jong Un ordered the North Korean military to step up its training in preparation for a "real war" and finally called for boosting the production of weapons, including tactical nuclear weapons.

Washington has repeatedly reiterated its "firm" commitment to South Korea's defense, including using the "full range of its military capabilities" that include "nuclear capabilities."