Why China stopped publicly urging for North Korean denuclearization

Xi and South Korean President Lee Jae Myung expressed a desire to maintain peace and stability in Northeast Asia, according to footage aired by state broadcaster China Central Television. The left-leaning Lee vowed to work with China to explore viable measures to foster peace on the Korean Peninsula.

Beijing had long openly opposed North Korea’s push to obtain nuclear weapons, often mentioning denuclearization as a goal with the regime of its leader, Kim Jong Un. But more recently, China has stopped making such calls publicly, opting to instead push for a “fair and impartial" approach toward peace on the Korean Peninsula—suggesting Beijing won’t contest Pyongyang’s de facto nuclear status.

That doesn’t mean South Korea can—or will—stop asking China for help in slowing Pyongyang’s efforts to build out its nuclear arsenal, even if the answer, ultimately, is no. Xi likely now sees more utility in keeping a nuclear-armed North close as tensions rise with the U.S. over Taiwan, security experts say. China’s sway looks also more limited, given how Kim’s nuclear stockpile and resolve in keeping his atomic bombs have only grown with time.

The shifting rhetoric on Kim’s nuclear arsenal reflects a new reality where China, despite remaining North Korea’s economic lifeline, increasingly lacks the incentive to apply pressure on Pyongyang to give up its nuclear weapons.

In late November, China, for the first time in nearly two decades, omitted any mention of North Korean disarmament from a periodically released defense white paper that articulates its stance on global threats. Meanwhile, the Trump administration in December made no reference to North Korea or denuclearization in the U.S.’s National Security Strategy document, which outlines Washington’s defense strategies and, in years past, called for the country to give up such arms. White House officials have subsequently said Washington is still committed to the “complete denuclearization" of North Korea.

The Trump administration hasn’t made Pyongyang’s denuclearization a central condition to Washington-Beijing relations, said Patricia M. Kim, a China expert at the Brookings Institution, a Washington, D.C.-based think tank. “Absent such pressure, Beijing has little reason to recalibrate its hands-off approach," she said.

Russia’s backing and China’s hesitation to openly call for denuclearization has emboldened North Korea to call its nuclear status “irreversible." With those two powers providing a shield against additional United Nations sanctions, Pyongyang has vowed to expand its nuclear program, leaving Washington and its allies facing a nuclear-armed axis.

On Sunday, Kim oversaw a test-launch of what Pyongyang’s state media claimed were hypersonic missiles—capabilities that underscored a need for a “nuclear war deterrent," the North Korean leader was quoted as saying.

China’s calculations have also likely shifted, now seeing North Korea as essential for pinning down American military resources that could otherwise be deployed to counter Chinese moves in the Taiwan Strait. Xi is also seeking to maintain its influence as North Korea’s primary patron and prevent Pyongyang from drifting further into Moscow’s orbit.

Ahead of Monday’s Xi-Lee summit, Seoul officials said the two leaders would discuss denuclearization, expressing South Korea’s concerns over Pyongyang’s evolving nuclear threats. Xi hosted Lee at a Chinese state guesthouse that once served as a venue for North Korean denuclearization talks. That round of diplomacy, starting in 2003, featured the two Koreas, China, Japan, Russia and the U.S. in an arrangement known as the “Six-Party Talks." The multilateral effort to curb Pyongyang’s nuclear program broke down as North Korea withdrew from the talks in 2009.

China, alongside Russia, backed tighter sanctions against the Kim regime as recently as 2017 during President Trump’s first term, when the U.N. passed sweeping restrictions after a spree of North Korean weapons tests. Since then, China has publicly supported North Korea’s denuclearization—at least until more recently, when it toned down its language to call for peace. Both China and Russia have shifted blame toward the U.S. for escalating military tensions.

Beijing’s influence on Pyongyang has diminished because of the Kim regime’s closer relations with Moscow, and Xi appears to have little power to bring North Korea back to the negotiating table to advance denuclearization, said Victor Cha, the Korea Chair at the Center for Strategic and International Studies, a Washington, D.C.-based think tank.

“The only one who could bring North Korea back to the table is probably Trump himself," Cha said. “But for North Korea there would have to be no conditions for denuclearization."

Write to Dasl Yoon at dasl.yoon@wsj.com