The leaders of South Korea and Japan on Monday sought to restore economic cooperation with China, their biggest trading partner, after years of souring relations, but their three-way talks were overshadowed by heightened tensions between China and the United States, Seoul and Tokyo’s most important military ally.
The trilateral meeting — featuring President Yoon Suk Yeol of South Korea, Prime Minister Fumio Kishida of Japan and Premier Li Qiang, the second-highest official in China — was the first in four and a half years.
Talks focused mainly on areas where common ground could more easily be found, such as protecting supply chains, promoting trade and cooperating on the challenges of aging populations and emerging infectious diseases. The leaders tiptoed around thorny regional security issues like Taiwan and North Korea.
“The three nations agreed to expand practical cooperation in a way their people can feel its benefits,” Mr. Yoon said during a joint news conference with Mr. Kishida and Mr. Li, announcing 2025 and 2026 as the “years of cultural exchanges” among the three nations.
But North Korea helped highlight the major differences among the three neighbors on Monday. Hours before their meeting began, it announced a plan to place a military spy satellite into orbit. It followed through after the summit ended, launching a long-range rocket carrying the satellite from its space station in northwestern North Korea.
The country is barred by United Nations Security Council resolutions from launching such rockets because they use the same technology needed to build intercontinental ballistic missiles.
North Korea’s increasingly aggressive military posture has deepened concerns in South Korea and Japan. The North has also expanded arms trade with Russia in defiance of U.N. sanctions, shipping artillery shells and missiles for Moscow’s war effort in Ukraine, according to American and South Korean officials. In return, Moscow is accused of providing energy and technological assistance that could help North Korea’s missile program.
South Korea and Japan have called on China, North Korea’s biggest benefactor, to use its economic influence to help rein in Pyongyang’s nuclear and missile programs. So far, Beijing has been reluctant to use that leverage, considering North Korea a buffer against the American military on the Korean Peninsula.
As the news conference was wrapping up in Seoul, 20 South Korean warplanes conducted an airstrike drill south of the inter-Korean border as a warning of “immediate and strong” retaliation against North Korean provocation.
China, Japan and South Korea had agreed to hold a trilateral meeting every year starting in 2008 to discuss regional cooperation. But the plan has often been disrupted by diplomatic spats and most recently by the pandemic. The meeting held in Seoul on Monday was the ninth such gathering and the first since December 2019.
During the yearslong gap, the strategic competition between Washington and Beijing has intensified, also souring relations between China and the two United States allies. China has flexed its military muscle and expanded its territorial ambitions in the South and East China Seas, while the United States, Japan and South Korea have increased joint military drills and strengthened missile defense and other security cooperation.
China’s ties with the two U.S. allies have become so testy in recent years that analysts observed that simply reviving the trilateral summit was an achievement. But common interests compelled Beijing and its two neighbors to revive it.
Mr. Yoon said on Monday that the three nations agreed to hold the summit meetings regularly.
The East Asian neighbors, which together account for more than one-fifth of global economic output, need regional stability and cooperation, especially in supply chains, to recover from their post-pandemic economic slowdown. Although Japan and South Korea consider the United States their most important ally, together hosting 80,000 American troops on their territories, their leaders have faced pressure at home from businesses vying to improve access to China.
China is betting that it can court Japan and South Korea by offering greater access to its market and diminish some of Washington’s influence. To that end, China has agreed to restart talks on a free-trade agreement between the three neighbors, emphasizing greater economic cooperation as a means to maintain regional peace and stability.
It has cast the United States as a meddler in Asian affairs that is pressuring Japan and South Korea to form a bloc to keep China’s development in check. Washington has imposed a wall of restrictions to deny Beijing access to the latest semiconductors, and is urging allies like Japan and South Korea to cooperate.
On Monday, Mr. Li indirectly criticized Washington by calling for a “multipolar” world order and opposing any attempt to create “blocs” and to “politicize” trade issues.
In recent years, Japan and South Korean have grown closer, improving relations long strained by historical disputes. They have also expanded trilateral military cooperation with the United States to deter North Korea and China.
Japan and South Korea urged China to address their increasing difficulty in doing business in China. Mr. Kishida called for the early release of Japanese nationals detained in China on suspicion of espionage.
During bilateral talks on Sunday, South Korea and China agreed to start new channels to discuss security issues and cooperation in supply chains, said Kim Tae-hyo, a deputy national security director in Mr. Yoon’s office.
Mr. Yoon’s policy of aligning South Korea more closely with the United States has overlapped with a sharp drop in South Korea’s exports to China. The United States this year replaced China as South Korea’s biggest export market for the first time in two decades, according to government data.
David Pierson contributed reporting.