A Chinese delegation led by Vice Premier Liu Guozhong has left for Pyongyang to attend North Korea's 75th anniversary celebrations.
North Korea marks its founding day on September 9.
Liu was at the head of a delegation that boarded a flight to Pyongyang from an international airport in Beijing on Friday.
The members are expected to attend a military parade.
The focus is on whether they will meet North Korean leader Kim Jong Un.
North Korea apparently aims to showcase its close ties with China at a time when the United States is stepping up security cooperation with Japan and South Korea.
In July, China sent a delegation to Pyongyang for the 70th anniversary of the Korean War armistice. The delegates handed the North Korean leader a letter from Chinese President Xi Jinping.