A senior Chinese official has arrived in North Korea to mark the 50th anniversary of a treaty of friendship between the two allies.
Footage from Associated Press Television News in Pyongyang shows Chinese Vice Premier Zhang Dejiang greeted by North Korean Vice Foreign Minister Kim Hyong Jun after arriving Sunday.
North Korean state media say Chinese President Hu Jintao has sent a letter to North Korean leader Kim Jong Il that says strengthening ties is Beijing's "unshakable strategic policy."
Kim traveled to China in May and Beijing and Pyongyang have recently begun a new joint economic project.
The countries fought together in the 1950-53 Korean War and China remains North Korea's most important ally.