The uncle of North Korean leader Kim Jong-un and a key guardian of Kim's new leadership embarked a visit to China on Monday for talks on joint development projects with China over two special economic zones in the North, Pyongyang's official news agency said.

The visit by Jang Song-thaek, vice chairman of the North's powerful National Defense Commission, came after Kim met with Wang Jiarui, chief of the Chinese Communist Party's international affairs office, in Pyongyang early this month and reportedly placed a priority on developing the North's moribund economy.

A delegation led by Jang, vice chairman of the North's National Defense Commission, left for Beijing earlier in the day, the North's Korean Central News Agency said in a brief report.

Jang will attend a third round of talks with Chinese officials on the development of Rason City on the northern tip of the Korean Peninsula and Hwanggumphyong, an island on the border with China, KCNA said.

The talks are "to discuss the joint development and joint management of Rason Economic Trade Zone and Hwanggumphyong and Wihwado Economic Zone," the report said.

The North's delegation, consisting of as many as 30 officials, arrived at an airport in Beijing at around 6:00 p.m. (Beijing time).

The KCNA report did not give details of Jang's itinerary, but diplomatic sources in Beijing said Jang is expected to return home on Saturday, after touring China's southern region and three northeastern provinces.

About eight months after inheriting North Korea after the death of his father, Kim Jong-il, the young Kim has appeared to cement his grip on power. Jang is the husband of Kim Kyong-hui, a sister of the late father of Kim.

In 2011, North Korea and China broke ground on Hwanggumphyong Island to develop it into an economic zone, a move that came on the heels of the late leader's trip to China to study the neighboring country's economic development.

Kim suddenly died of heart attack last December, but the North has said it will uphold the policies of its late leader to help achieve a thriving socialist country under the leadership of the new leader, who is believed to be in his late 20s.

China has been trying to lure its impoverished ally to embrace the reform that lifted millions of Chinese out of poverty and helped Beijing to become the world's second-largest economy.

(Yonhap News)