President Xi Jinping on Sunday told his North Korean counterpart Kim Jong-un that Beijing hoped to "deepen friendly... cooperation" with Pyongyang, as the two leaders exchanged messages to mark a major diplomatic anniversary.

State media in both countries said Xi and Kim exchanged congratulatory messages on Sunday to mark the 75th anniversary of the establishment of diplomatic relations.

"China is willing to work with the North Korean side... to strengthen strategic communication and coordination, deepen friendly exchanges and cooperation, (and) write a new chapter in the traditional bilateral friendship," Xi said.

He added that Beijing and Pyongyang "have worked closely to promote regional peace and stability, and uphold international fairness and justice."

North Korean state news agency KCNA reported that Kim said Pyongyang "will steadily strive to consolidate and develop the friendly and cooperative relations between (North Korea) and China". (AFP/Xinhua)