North Korea said Friday it has started to build a management office for a special economic and trade zone to be jointly developed and operated by the North and its strongest ally, China.

According to the Korea Central News Agency, dozens of high-ranking officials from the both countries attended a groundbreaking ceremony for the office building of the Rason Economic and Trade Zone Management Committee.

The North has been ramping up efforts to develop special economic zones in Rason, the North's northern tip, and on Hwanggumphyong and Wihwa islands, bordering China.

South Korea's relations with the North have been frozen since President Lee Myung-bak took office in 2008, virtually cutting inter-Korean economic cooperation.

In response, the North has deepened its ties with China in an effort to help revive its moribund economy alongside stricter international sanctions following its nuclear and rocket tests. In 2011, Pyongyang's trade with China accounted for about 89 percent of its total, according to the BOK.

The report said the potential success of developing such economic zones is likely to serve as a catalyst for the North's opening over the long haul, but will also make it more economically reliant on China.

Meanwhile, the KCNA said a ceremony also took place for the opening of the Rajin-Wonjon road in the Rason Economic and Trade Zone. (Yonhap News)