Presidents Yoon Suk Yeol and Joe Biden will proclaim a strengthened nuclear shield at the White House, and as part of that announcement, a US nuclear missile submarine will make its first trip to South Korea in decades, according to an official.

In order to increase deterrence in the face of North Korea’s aggressive nuclear operations, a senior US official stated that actions unveiled on Wednesday are unprecedented since the height of the Cold War.

Biden and Yoon, at the White House for a state visit, will issue a document called the Washington Declaration outlining how in addition to a beefed-up US military umbrella, the United States will increase information sharing with Seoul.

The arrangement — responding to ever growing tension over communist North Korea’s missiles tests and nuclear arsenal — echoes moves last seen when the Washington oversaw the strategic defense of Europe against the Soviet Union.

“The United States has not taken these steps, really, since the height of the Cold War with our very closest handful of allies in Europe. And we are seeking to ensure that by undertaking these new procedures, these new steps, that our commitment to extended deterrence is unquestionable,” a senior official said ahead of the Biden-Yoon meeting.

Officials, speaking on condition of anonymity, stressed that there are no plans to station US nuclear weapons in South Korea — a difference from the Cold War, when US strategic weapons were deployed to Europe. In addition, Seoul will reiterate its pledge in the declaration not to seek its own nuclear arsenal.

“We’ll announce that we intend to take steps to make our deterrence more visible through the regular deployment of strategic assets, including a US nuclear ballistic submarine visit to South Korea, which has not happened since the early 1980s,” a senior official said.

“We’ll strengthen our training, our exercises and simulation activities to improve the US-ROK alliances approach to deterring and defending against DPRK threats, including by better integrating ROK conventional assets into our strategic planning,” the official said, referring to South and North Korea by their official acronyms.

In addition to submarines, there will be a “regular cadence” of other major platforms, “including bombers or aircraft carriers,” the official said. But there will be “no basing of those assets and certainly not nuclear weapons.”

Despite more shared information and planning, a US official stressed that use of American nuclear weapons remains under sole authority of the US president.

An official said that steps are being taken in advance to defuse any potential tensions with Beijing over the tougher military posture.

“We are briefing the Chinese in advance and laying out very clearly our rationale for why we are taking these steps,” the official, adding that the Biden administration is “disappointed that China has been unprepared to use its influence” on North Korea.

Yoon is only the second foreign leader invited for a state visit by Biden and he and his wife were set to be greeted with full military honors at the White House. The two presidents were holding talks in the Oval Office before giving a press conference in the Rose Garden.

The day will round off with a lavish state dinner.

On Tuesday, Yoon and Biden visited the Korean War Memorial, depicting life-sized steel statues of US soldiers marching during the 1950-53 war against the communist north.

Yoon also laid a wreath at the Tomb of the Unknown Soldier in Arlington National Cemetery and joined US Vice President Kamala Harris for a tour of a NASA space facility near Washington.

Washington and Seoul are also highlighting the strong cultural links, something emphasized by Netflix’s announcement of a $2.5 billion investment in South Korean content. Netflix CEO Ted Sarandos met with Yoon in Washington on Monday.