North Korea and China have agreed to ramp up their joint development of economic zones, China's commerce ministry said Tuesday, as Pyongyang's new leader is stepping up economic diplomacy in efforts to boost his country's struggling economy.

Under the agreement, the two sides will set up two management committees to push forward with the development of special economic zones in Rason City, and the Hwanggumphyong and Wihwa islands, according to China's Ministry of Commerce.

Pyongyang and Beijing also plan to expand cooperation on agriculture and technology as well as set up telecommunications, supply electricity and train personnel.

"Both sides reached the consensus that the cooperation in developing the two economic zones has yielded impressive results and entered the stage of substantial development," China's commerce ministry said in a press release.

The agreement comes on the heels of a high-level meeting between the two allies attended by China's commerce minister Chen Deming and North Korea's Jang Song-thaek, the powerful uncle and key guardian of its leader Kim Jong-un.

Pyongyang said Monday a North Korean delegation led by Jang, vice chairman of the North's National Defense Commission, left for Beijing to attend the third meeting of the North-China Joint Guidance Committee, which deals with the two's joint development of special economic zones.

Seoul officials had said the ongoing China visit is most likely to be focused on ramping up economic cooperation between the two allies.

The unusually large delegation of about 50 officials may "appeal for China's generous investment and support" for the economic zones, which largely remain moribund since being jointly launched with China, an official said on condition of anonymity.

Jang's signature role as a promoter of North-China economic cooperation projects in the North also indicates his delegation, largely composed of economy officials, may try to secure sufficient investment from its closest ally.

"The interesting point to focus on is to what extent China decides to meet the North's (investment demand)," the official said, indicating the North may be expecting "bold" investments from its ally.

"But China may not be able to give all the North wants" because of the superpower's international reputation, he said. "It will be an effective idea for the North to take steps that the global community welcomes" to help secure more overseas investment, he added.

Responding to media speculation that Jang may meet China President Hu Jintao and Vice President Xi Jinping, the official said it is "likely."

North Korean watchers said Jang's six-day visit may encompass broader economic and political assistance requests than what the visit appears to be targeting.

"Viewing from a wider perspective, the latest North Korean delegation visit seems to be focused on securing funds to be used for general economic upgrade (efforts)," a source in Beijing said, referring to the North's so-called "June 28 new economy management system" adopted to reform its sickly economy.

"Vice chairman Jang and his delegation are likely to contact China's party, political and military officials to appeal for comprehensive measures," the source said.

North Korea seems to be trying to use the Rason and Hwanggumphyong joint economic zones to secure legitimate investment from China, but China may have a different idea, the source also noted.

"The ongoing visit only appears to be targeting North-China economic cooperations, but this meeting can be expanded to cover discussions on diplomatic issues like the North's nuclear programs," said Zhang Liangui, director of Research Institute for International Strategic Studies at the Party School of the Communist Party of China Central Committee.

Meanwhile, the delegation led by Jang is reported to have departed Beijing for Changchun, the capital of Jilin province.

Jang is expected to visit Liaoning and Jilin provinces ahead of meeting with China's President Hu Jintao and Premier Wen Jiabao in Beijing. The North Korean official is likely to return home on Saturday. (Yonhap News)