South Korea to vow not to build own nukes as Yoon meets with Biden

South Korea will make clear on Wednesday that it will not seek its own nuclear weapons, as President Yoon Suk-yeol meets with U.S. leader Joe Biden in Washington amid growing concerns in Seoul over the United States' commitment to defending its Asian ally from North Korea’s increasingly potent missile and nuclear arsenal.

The pledge will be part of a new agreement — known as the Washington Declaration — that also creates a fresh bilateral nuclear consultation mechanism based on U.S.-European Cold War-era frameworks, according to senior U.S. officials, who said the document had been under discussion with Seoul “for months.”

Once a fringe position, support for the idea of South Korea developing its own nuclear bombs has spread rapidly in the country as doubts grow about the United States’ willingness to potentially sacrifice San Francisco for Seoul, after North Korean nuclear and missile breakthroughs have put American cities firmly within striking distance.

A spate of recent surveys show that a majority of South Koreans — including an astounding 71% in a wide-ranging poll taken in February last year — now believe the country should develop its own nuclear weapons, a move Yoon had earlier hinted Seoul could pursue.

But ahead of Yoon’s meeting with Biden, U.S. officials were quick to pour cold water on both the idea of an indigenous South Korean nuclear program and a return of U.S. nuclear weapons to the peninsula after the last bomb was removed in 1991 as the Cold War winded down.

The officials said Tuesday that the Washington Declaration would take a two-pronged approach to preventing conflict with North Korea and managing regional nonproliferation risks by highlighting both the strength of the United States’ “nuclear umbrella” and reaffirming South Korea’s “enduring commitment” to the Nuclear Non-Proliferation Treaty.

In terms of better deterring and responding to Pyongyang, the new agreement will also see the creation of the U.S.-ROK Nuclear Consultative Group, a regularly meeting bilateral grouping intended to give Seoul a weightier voice in “planning for major contingencies,” the officials said, using the acronym for the South’s formal name, the Republic of Korea.

“In many respects, this is modeled after what we did with European allies during the height of the Cold War,” one senior U.S. official said, speaking on condition of anonymity.

To backstop the U.S. policy of extended deterrence — a pledge that its nuclear arsenal will be used to dissuade or respond to a North Korean attack on the South — that official said Yoon and Biden will also announce “more visible” steps on the Korean Peninsula.

These will include the regular deployment of U.S. “strategic assets” such as heavy bombers and aircraft carriers, as well as the first visit to South Korea by a U.S. nuclear-powered ballistic missile submarine since the early 1980s, the official said. Bolstered information-sharing and strengthened military exercises, including with Japan, will also be part of the package.

The Washington Declaration “is meant to be crystal clear that the United States and ROK understand the stakes and are prepared to rise and meet them,” according to the senior U.S. official.

The more muscular allied approach comes as the North Korean regime has repeatedly delivered fiery warnings over the increased presence of U.S. strategic assets near the Korean Peninsula, including a threat by leader Kim Jong Un’s sister to turn the Pacific into a “firing range” for its increasingly sophisticated missiles.

In recent months, the North has passed a new law declaring its nuclear status "irreversible,” while testing and training with a variety of powerful new weapons such as tactical nuclear warheads that could be used on the peninsula and against Japan, as well as advanced intercontinental ballistic missiles believed to be capable of delivering nuclear bombs anywhere in the U.S.

While the North’s saber-rattling has long been part of its playbook, its progress with its nuclear program and growing concerns over the U.S. defense commitment to the South has left Washington scrambling for options to prevent Seoul from inching closer to a nuclear capability — a move that would prove incredibly destabilizing for the region and even the globe.

Observers say allowing South Korea to go nuclear — something it attempted before in the 1970s — would unleash a domino effect that prompts others, including latent nuclear power Japan, to build their own arsenals, spelling the end of the global nuclear nonproliferation regime.

“We think this is a very important contribution to the maintenance of peace and stability,” the senior U.S. official said. “It is often, I think, overlooked that one of the great achievements of American foreign policy ... is that a large number of countries in the Indo-Pacific who have advanced capabilities have chosen not to build nuclear weapons on the strength of the American” defense commitment.

“We believe that those efforts should be preserved, even in the face of challenges from North Korea, and elsewhere.”

Yoon’s trip to Washington to celebrate the 70th anniversary of the U.S.-South Korea alliance will also underscore the depths of the two leaders’ personal connection, with the talks marking his fifth meeting with Biden and the first state visit to the White House by an Indo-Pacific leader.

But those personal ties are likely to be tested after the emergence earlier this month of leaked U.S. intelligence documents suggesting Washington spied on Seoul as it debated whether to send artillery rounds to Ukraine.

Yoon’s government has said it discussed the issue with the Biden administration, with the two sides agreeing that “a significant portion” of the documents were fabricated — though it did not specify which were faked.

In an interview with NBC News that aired Tuesday, Yoon downplayed any lasting impact from the incident.

"I believe this matter is no reason to shake the ironclad trust that supports the U.S.-South Korea alliance, because it is based on shared values like freedom," Yoon said through an interpreter. "The most important thing is the trust. When you have that trust, you don't get shaken."

Yoon is also likely to face at least some pressure from Biden to do more to aid Ukraine in repelling Russia’s invasion of its neighbor, with the substantive discussions “on what comes next for (South) Korean support to Ukraine” expected, another U.S. official said separately.

“We'll want to know what Seoul is thinking about, what the future of their support might look like,” the official added.

As for improving ties between South Korea and Japan in the wake of Yoon’s trip to Tokyo for talks with Prime Minister Fumio Kishida last month, Biden will highlight the United States’ strong support for what American officials said was Yoon’s “courageous determination to build stronger bridges with Japan.”

That relationship has improved in recent weeks after Yoon’s proposal for resolving a long-festering dispute over compensation for Japan’s use of wartime labor during its 1910-45 occupation of the Korean Peninsula. The move paved the way for the opening of other avenues of cooperation, most pressingly on the security front.

The Biden administration says bolstered ties between the mutual U.S. allies are “absolutely necessary” for responding appropriately and effectively to the North Korean threat and other regional concerns.

Still, the senior U.S. official acknowledged that much work remains to be done.

“We believe that we're still at early stages of that sort of rapprochement process between Japan and South Korea. This is an initial set of steps that should and will be built on.”