Destitute North Korea's move to jointly build a free trade zone with China has made a "remarkable success," a Pyongyang official said Wednesday, indicating that the North's nuclear standoff has not soured economic ties with Beijing.

China has built "several industrial zones, modern-farming facilities and plants" at the free trade zone in North Korea's northeastern cities of Rajin and Sonbong, known as Rason, said Hwang Ik-hwan, a senior researcher at the North's foreign ministry-affiliated Institute for Disarmament & Peace.

"The joint development and management of the Rason economic trade zone with China is being carried out at the highest speed and a remarkable success has been achieved," Hwang told an international conference in Tianjin, organized by the China Foundation for International Studies (CFIS) and the China International Institute for Strategic Society.

China, North Korea's key ally and major trading partner, has reportedly agreed to invest about US$3 billion in developing the North's free trade zone as its export base. The ports at Rajin and Sonbong give China's northeastern provinces direct access to the East Sea off the Korean Peninsula's east coast.

"The DPRK (North Korea) government is taking positive measures to speed up economic development by promoting economic cooperation with other countries and attracting investment," Hwang said.

Although China appears to have become increasingly frustrated with North Korea, particularly after the North's third nuclear test in February, Beijing has been deepening its economic cooperation with Pyongyang.

Hwang cited an annual trade exhibition, which was held last month in the Chinese border city of Dandong, as a "typical example of growing economic cooperation" between the two nations.

"More than 10,000 people from 20-odd countries, including the DPRK and China, participated in the exhibition," Hwang said of the North Korea-China Economic, Trade, Culture and Tourism Expo.

"Over 90 trade cooperation agreements valued at $1.6 billion were signed at the end of the exhibition in Dandong," Hwang said.

North Korea's young leader Kim Jong-un, who took power after his father, Kim Jong-il, died in late 2011, has shown no signs of abandoning its nuclear weapons program and declared that Pyongyang will simultaneously pursue nuclear and economic development.

Hwang confirmed that the North's leader is trying to revive the nation's moribund economy.

"The dear respect marshal Kim Jong-un has put forward a new idea of building tourist zones in various parts of the country  in order to attract more tourists," Hwang said.

Kim "also instructed officials to establish economic development zones in all provinces of the country and develop those economic development zones in accordance with their own situations and specific characters," Hwang said.

"In this regard, the National Economic Development Committee was newly organized in May this year with the purpose of strengthening the economic cooperation and exchanges with other countries and encourage investments in the economic zones," Hwang said.

During the forum, a Chinese expert advised North Korea that it could not achieve economic development without giving up its ambition of nuclear weapons.

Cao Shigong, a specialist of Korean affairs at the Chinese Association of Asia-Pacific Studies, said, "North Korea's declaration of simultaneously pursuing nuclear and economic development will not be successful."

"North Korea must give up its nuclear ambition in order to enhance economic development," Cao said. (Yonhap News)