Kim Jong Un promised this week to improve relations with China, North Korea’s most critical trade partner.

Kim said Monday he’d make efforts to “further consolidate and develop the traditional DPRK-China friendly relations,” according to North Korea’s Central News Agency, Yonhap News Agency reported.

DPRK stands for the Democratic People’s Republic of Korea.

The Hermit Kingdom ruler’s remarks were in response to a congratulatory letter dispatched earlier this month by Chinese President Xi Jinping for the 75th anniversary of the Workers’ Party, the ruling party in the North.

Xi said China intended to “successfully defend, consolidate and develop” the bilateral relations, Yonhap said.

North Korea heavily relies on China for its food, arms and fuel.