U.S. to send nuclear submarines to dock in South Korea for first time since 1980s (2025)

Presidents Joe Biden and Yoon Suk Yeol on Wednesday are signing an agreement that includes plans to have U.S. nuclear-armed submarines dock in South Korea for the first time in more than 40 years, a conspicuous show of support to Seoul amid growing concern about nuclear threats by North Korea. The White House released the agreement, and senior Biden administration officials spelled out the details ahead of time.

The planned dock visits are a key element of what's being dubbed the "Washington Declaration," aimed at deterring North Korea from carrying out an attack on its neighbor. It was unveiled as Mr. Biden hosts Yoon for a state visit during a moment of heightened anxiety for both leaders over an increased pace of ballistic missile tests by North Korea over the last several months. In return for the submarines, three senior White House officials said South Korea will reaffirm its commitment to the Nuclear Nonproliferation Treaty, known as the NPT, which bars countries from developing their own nuclear weapons.

"Going forward, the United States will further enhance the regular visibility of strategic assets to the Korean Peninsula, as evidenced by the upcoming visit of a U.S. nuclear ballistic missile submarine to the ROK, and will expand and deepen coordination between our militaries," the Washington Declaration says. "Furthermore, the United States and ROK will strengthen standing bodies for consultations on extended deterrence, including the Extended Deterrence Strategy and Consultation Group, to better prepare the Alliance to defend against potential attacks and nuclear use and conduct simulations to inform joint planning efforts."

In a White House Rose Garden press conference alongside his South Korean counterpart Wednesday, Mr. Biden confirmed plans for nuclear-capable submarines. He also had a message for North Korea.

"Look, a nuclear attack by North Korea against the United States or its allies or partisans — or partners — is unacceptable and will result in the end of whatever regime were to take such an action," Mr. Biden said. "What the declaration means is that we're going to make every effort to consult with our allies when it's appropriate, if any action is so called for. Certainly, we've talked about this and some other things today but the bottom line here is, there's even closer cooperation, closer consultation."

Yoon, through a translator, said the leaders have decided to "significantly strengthen" their extended deterrence to achieve something that isn't just a "false peace." Yoon said Mr. Biden, through the "Washington Declaration," has reaffirmed his "ironclad commitment" toward extended deterrence.

"Sustainable peace on the Korean Peninsula does not happen automatically," Yoon said through his translator. Yoon added, "our two countries have agreed to immediate bilateral presidential consultations in the event of North Korea's nuclear attack and promise to respond swiftly, overwhelmingly and decisively using the full force of the Alliance including the United States' nuclear weapons."

The three senior Biden administration officials, who briefed reporters on the condition of anonymity ahead of the official announcement, said that aides to Mr. Biden and Yoon have beenworking on details of the plan for monthsand agreed that "occasional" and "very clear demonstrations of the strength" of U.S. extended deterrence capabilities needed to be an essential aspect of the agreement.

According to The Wall Street Journal, Mr. Biden and Yoon first met in Cambodia in November and in February, agreed to make the declaration the centerpiece of Yoon's current visit to Washington.

The agreement seeks to assuage South Korean fears over the North's aggressive nuclear weapons program and to ward off the country from restarting its own nuclear program, which it gave up nearly 50 years ago when it signed the Nuclear Non-Proliferation Treaty. The U.S. and South Korea also would coordinate more deeply on nuclear response strategy in the event of the North attacking the South — but operational control of such weapons would remain in U.S. control, and no nuclear weapons are being deployed onto South Korean shores.

The agreement also calls for the U.S. and South Korean militaries to strengthen joint training and better integrate South Korean military assets into the joint strategic deterrence effort.

As a candidate for the presidency last year, Yoon said he would call for the increased deployment of U.S. bombers, aircraft carriers and nuclear submarines to South Korea as he looked to offer a firmer response to the North's threats than his predecessor Moon Jae-in.

In the midst of the Cold War in the late 1970s, U.S. nuclear-armed ballistic missile submarines made frequent port visits to South Korea, sometimes two to three visits per month, according to the Federation of American Scientists. It was a period when the U.S. had hundreds of nuclear warheads located in South Korea.

But in 1991, the United States withdrew all of its nuclear weapons from the Korean Peninsula, and the following year Seoul and Pyongyang signed a joint declaration pledging that neither would "test, manufacture, produce, receive, possess, store, deploy or use nuclear weapons." But as the North has repeatedly violated the joint declaration over the years, there's been increased support in South Korea for the United States to return nuclear weapons to the country.

One Biden administration official cautioned it is "crystal clear" that there are no plans by the administration for "returning tactical or any other kind of nuclear weapon to the Korean Peninsula." Instead, administration officials said they envision that the visit of ballistic missile submarines will be followed by the U.S. military more regularly deploying assets such as bombers or aircraft carriers to South Korea.

Mr. Biden on Wednesday also emphasized the U.S. is "not gonna' be stationing nuclear weapons on the peninsula."

North Korea's increasing nuclear threats, along with concerns about China's military and economic assertiveness in the region, have pushed the Biden administration to expand its Asian alliance. To that end, Mr. Biden has thrown plenty of attention at Yoon as well as Japanese Prime Minister Fumio Kishida. Next week, Mr. Biden will host Philippine President Ferdinand Marcos Jr. for Oval Office talks.

In the past year, North Korea has been steadily expanding its nuclear arsenal, while China and Russia repeatedly block U.S.-led efforts to toughen sanctions on the North over its barrage of banned missile tests.

Asked whether the Washington Declaration risks irritating China, senior administraiton officials bemoaned China's lack of action to rein in North Korea and called the declaration "a response — a prudent, careful, strategic response to sustained provocations that, frankly, have been excused or certainly not reined in on by China."

The stepped-up testing by North Korea includes the flight-testing of a solid-fuel intercontinental ballistic missile for the first time earlier this month. The recent test is seen as a possible breakthrough in the North's efforts to acquire a more powerful, harder-to-detect weapon targeting the continental United States.

Besides nuclear deterrence, Mr. Biden and Yoon, and their aides, discussedRussia's ongoing war in Ukraine. The Biden administration has praised South Korea for sending some $230 million in humanitarian aid to Kyiv, but Mr. Biden would welcome Seoul taking an even bigger role in helping the Ukrainians repel Russia.

Yoon's visit comes just weeks after the leaks of scores of highly classified documents that have complicated relations with allies, including South Korea. The papers viewed by The Associated Press indicate that South Korea's National Security Council "grappled" with the U.S. in early March over an American request to provide artillery ammunition to Ukraine.

The documents, which cited a signals intelligence report, said then-NSC Director Kim Sung-han suggested the possibility of selling the 330,000 rounds of 155 mm munitions to Poland, since getting the ammunition to Ukraine quickly was the United States' ultimate goal.

The Bidens held a state dinner for Yoon and his wife. Mr. Biden toasted to the U.S.-ROK alliance.

"To our partnership, to our people, to the possibilities, to the future the Republic of Korea and the United States will create together," Mr. Biden said. "May we do it together for another 170 years."

Yoon, too, toasted to the two nations' alliance.

"We will together embrace the future of the alliance undergirded by our shared core values of freedom, democracy, the rule of law and human rights," Yoon said.

The South Korean president concluded his speech by saying, "A good friend is like a four-leaf clover — hard to find and lucky to have."

In:
• South Korea