Thirteen cities and counties in Hebei Province will have their area codes changed to 010, the series of numbers to dial before the capital city's fixed-line phone numbers, an official from Hebei said in Beijing on March 11, Beijing Youth Daily reported. This indicates an important step towards the coordinated development of the Beijing-Tianjin-Hebei economic bloc.

Hebei has formulated a strategic plan to promote the formation of the Beijing Economic Circle, which aims to realize the balanced development of Beijing, Tianjin Municipality and Hebei Province, Wang Fuqiang, inspector of Hebei's Industry and Information Technology Department, said during a trilateral meeting on regional collaborative development between his organization, the Beijing Municipal Commission of Development and Reform and the Tianjin Planning Bureau.

These cities and counties, adjacent to Beijing, include Zhuozhou, Laishui, Zhuolu, Huailai, Sanhe, Xianghe and two districts in Langfang.

Under the plans, the mobile network of Beijing will cover these cities and counties, which indicates there will be no roaming charges for mobile users traveling between Beijing and these areas.

More efforts will be made to promote the integrated development of the capital city and these areas.

Wang said, "It's an important step towards the coordinated development of the Beijing-Tianjin-Hebei economic bloc."

Hebei is now waiting for the central government's approval, Wang noted.

Beijing, Hebei and Tianjin have signed strategic cooperation agreements to further enhance collaborative development between the three regions, Li Shixiang, deputy mayor of Beijing and a deputy to the 12th National People's Congress (NPC), said on Mar. 7.

"The three have also established a mechanism on collaborative industrial development," Li said. "Beijing's Zhongguancun Science Park has set up a high-tech industrial park in Tianjin, and Beijing Automotive Group (BAIC) is also considering setting up a new plant in Cangzhou, Hebei."

In late 2013, the capital city also developed a mechanism with Hebei to support collaborative efforts in containing air pollution.

The concept of the Capital Economic Circle was proposed by the National Development and Reform Commission (NDRC) 10 years ago. It appeared in the 12th Five-Year National Development Plan (2011-2015) in 2011, aiming to form an economic hub in the Bohai Bay area, with Beijing as the core amid the three neighboring provincial regions. The economic circle will involve more than 10 cities and counties surrounding Beijing to help improve urban functions, optimize their industrial layout and balance resource allocation.

In late February 2014, Chinese President Xi Jinping called for the integrated development of the three provincial regions, highlighting the strategic importance of the newly developed ideas.

The NDRC is expected to roll out the plan for the Capital Economic Circle before June, according to media reports.