SEOUL — North Korean leader Kim Jong Un returned from a surprise one-day trip to the Chinese border city of Dandong, where he visited a historic Korean War memorial, North Korean state media said on Sunday.

Mr. Kim visited the city on Saturday and returned by road, crossing a newly opened bridge that connects North Korea to its biggest international backer and trading partner. The quick trip symbolized a push by Beijing and Pyongyang to expand trade ties.

North Korean state media emphasized the historical weight of the visit, which came a day before the anniversary of China joining the Korean War on Pyongyang’s side. The bilateral relationship is an “unbreakable” bond forged during the 1950-1953 conflict between North Korea and the US-backed South, state media said.

The two Koreas are technically still at war after the conflict ended in an armistice, rather than a peace treaty.

Mr. Kim said during his tour that the North Korean people would “forever remember the glorious years of fighting alongside the Chinese people” and pass down “generational gratitude to the Chinese people who helped our revolution with blood,” state news agency KCNA reported.

Beijing and Pyongyang have been seeking to bolster their economic relationship ahead of a trip to the region by US President Donald J. Trump next month. It also highlights a delicate diplomatic balancing act by Pyongyang, which has also been deepening military ties with Russia in the past two years.

Guided by Wang Huning, the fourth-highest ranking official in the Chinese Communist Party, Mr. Kim visited Dandong’s Memorial Hall of the War to Resist US Aggression and Aid Korea, accompanied by a high-level North Korean delegation that included his sister, Kim Yo Jong, and Foreign Minister Choe Son Hui.

Touring the memorial, Mr. Kim viewed an archival photograph of his grandfather, North Korean founder Kim Il Sung, and Mao Zedong, founder of the modern Chinese state, footage from North Korea’s state-run television KRT showed.

Mr. Kim presented a commemorative plaque featuring Kim Il Sung as a gift to the museum before holding a formal meeting with Mr. Wang and inspecting a bus factory in Dandong.

Mr. Kim last visited Beijing in September 2025 for a military parade, and Chinese President Xi Jinping visited North Korea in June.

“Enjoying a bird’s-eye view at the middle point of the newly inaugurated bridge, Comrade Kim Jong Un expressed expectation that the bridge would undoubtedly and correctly fulfill its historic mission of linking the two countries and firmly joining the minds of the peoples of the two countries,” KCNA reported. — Reuters