Washington: The US will strengthen the deterrence it provides South Korea against nuclear threats, including by deploying a nuclear-armed submarine to the country - in turn securing a pledge from Seoul to honour commitments to not pursue its own atomic arsenal.
US President Joe Biden and South Korean President Yoon Suk Yeol will announce the agreement when they meet Wednesday at the White House, according to senior American administration officials who spoke on condition of anonymity.
The so-called Washington Declaration will lay out steps to bolster security on the Korean Peninsula, including through more regular deployments of nuclear-armed submarines and by involving South Korea in strategic planning for nuclear contingencies, they said.
The move to deploy such a sub to South Korea temporarily is significant and hasn't happened since the early 1980s, US officials told reporters. The US will also strengthen training, exercises and simulation activities to improve cooperation in defending against threats from North Korea.
The White House envisions the sub deployment to be followed at regular intervals by visits of other assets, such as bombers and aircraft carriers. But there's no plan for permanent stationing of the assets on the peninsula.
The level of support will be similar to that provided to Europe under the US nuclear umbrella during the height of the Cold War, according to the officials. The arrangement does not mean US nuclear weapons would be deployed on South Korean soil, they said.
The security package comes after months of North Korean ballistic missile launches laced with threats of further nuclear tests. The US has flown bombers and deployed submarines in a show of force against North Korea and to soothe anxiety in South Korea over aggression by Kim Jong Un's regime.
Yet those actions have done little to calm the growing sentiment among South Koreans that the country should seek its own nuclear weapons to deter Kim.
Yoon in the past had suggested his country could seek its own nuclear option if North Korea kept up its provocations but has backtracked.
Possible fallout?
The agreement could trigger an outcry from Pyongyang and Beijing.
The Biden administration briefed China on the Washington Declaration and clearly laid out its intentions, the officials said. China should understand that the US steps are intended to ease security concerns in the region, according to the officials.
The US has been disappointed that officials in Beijing haven't used their influence with North Korea to force the regime to disarm its nuclear arsenal or reduce its provocations, they said.
Washington remains committed to diplomacy with North Korea and urges Kim's regime to return to talks.
Yoon arrived in Washington on Monday. He will sit down for formal talks with Biden on Wednesday.
Yoon attended a summit in March with Prime Minister Fumio Kishida of Japan, another nation that hosts American troops.