Chinese President Xi Jinping has pledged to steer relations with North Korea toward "long-term, sound and stable development," in a message to North Korean leader Kim Jong-un reported by Pyongyang's state media on Sunday. The exchange underscores the two neighbours' efforts to consolidate a relationship that carries significant weight across a tense region.

Xi's message was a reply to a congratulatory letter from Kim, sent on 1 July to mark the 105th anniversary of the founding of the Chinese Communist Party (CCP). In it, Xi said the CCP and North Korea's ruling Workers' Party of Korea were both "Marxist ruling parties" that had stood together for national independence across generations, and vowed to guide relevant sectors and regions of both countries toward the full implementation of the agreements reached between them. Kim, for his part, described their recent summit as a "historic occasion" and reaffirmed it was North Korea's "steadfast stand" to continue strengthening ties with Beijing.

The exchange follows Xi's rare two-day state visit to Pyongyang — North Korea's capital — in early June, his first trip to the country in seven years. During that visit, the two leaders agreed to deepen cooperation and strengthen high-level communication. The correspondence now arrives just days before 11 July, when the two countries are set to mark the 65th anniversary of the signing of the Treaty of Friendship, Cooperation and Mutual Assistance, a foundational document in the China–North Korea relationship.

The diplomatic warmth comes against a backdrop of rising tensions on the Korean Peninsula and beyond. North Korea has significantly expanded its military cooperation with Russia, sending soldiers and munitions to support Moscow's invasion of Ukraine — a development that has drawn sharp criticism from Western governments and sharpened concerns in Seoul and Washington. Despite these shifting alignments, China remains by far North Korea's most important economic partner, accounting for nearly 98 per cent of the country's foreign trade in 2024.

The renewed pledges of solidarity matter because China's relationship with North Korea shapes the broader security architecture of East Asia. Beijing has historically served as both Pyongyang's economic lifeline and its principal diplomatic shield. Xi's language — emphasising shared socialist purpose and long-term stability — signals that China intends to maintain that role even as North Korea deepens ties with Moscow, a triangular dynamic that analysts see as complicating international efforts to manage nuclear and security risks on the peninsula.