A senior Chinese diplomat will visit North Korea from Friday as a special envoy of Chinese President Xi Jinping, the government announced on Wednesday, amid continued tensions over Pyongyang's nuclear and missile programs.

China has repeatedly pushed for a diplomatic solution to the crisis, but in recent months has had only limited high-level exchanges with North Korea. February last year was the last time China's special envoy for North Korea visited the country.

In a brief dispatch, the official Xinhua news agency said Song Tao, who heads the ruling Communist Party's external affairs department, would leave for North Korea on Friday.

He will "inform the DPRK of the 19th CPC National Congress and visit the DPRK", Xinhua said, using the North's official name and also referring to the recently concluded Communist Party Congress in China where Xi further cemented his power.

North Korea's KCNA news agency confirmed the visit, but said only that it would take place "soon."

It is not clear how long Song could stay, but he has already visited Vietnam and Laos to inform them of the results of the congress, a typical courtesy China extends other communist countries after such important meetings.

Song's department is in charge of the party's relations with foreign political parties, and has traditionally served as a conduit for Chinese diplomacy with North Korea.

A department official said last month that China's Communist Party continues to hold talks and maintain contacts with its North Korean counterpart, describing the two countries friendship as important for regional stability.

China's new special envoy for North Korea, Kong Xuanyou, who took up his position in August, is not believed to have yet visited the country since he assumed the job.