In a congratulatory message to Xi marking the 105th anniversary of the founding of the Communist Party of China, Kim said it was Pyongyang's "steadfast stand" to steadily develop relations with Beijing, according to the North's state-run Korean Central News Agency.
"It is the steadfast stand of our Party and government to steadily develop the DPRK-China friendly relations with long and historical roots and with socialism as their core," Kim said in the message.
"The recent Pyongyang summit was a historic occasion of deepening the comradely friendship and trust between us," Kim said, adding that the two leaders had reaffirmed their "unshakable will" to advance traditional bilateral ties.
Kim also said he was ready to work with Xi to further develop North Korea-China "friendly and cooperative relations", calling them "the common wealth of the peoples of the two countries".
More from WorldThe message comes weeks after Xi made a rare visit to Pyongyang, where the two leaders pledged to strengthen ties such as Pyongyang's increasingly close military relationship with Russia.
During the summit, Kim and Xi adopted what North Korean state media described as a "far-reaching blueprint" for bilateral relations and pledged to develop their traditional friendship into "the most powerful and strategic relations".
Xi also pushed for closer diplomatic, law enforcement and military cooperation, according to Chinese state media.
While Pyongyang has drawn closer to Moscow by supplying troops and weapons for Russia's war in Ukraine, China remains North Korea's largest economic partner, accounting for nearly 98 percent of the country's foreign trade in 2024, according to South Korea's Ministry of Economy and Finance.
