BEIJING — A draft plan to turn the Guangdong-Hong Kong-Macao greater bay area into the world's largest bay area in terms of GDP by 2030 has been filed with the national economic planner, according to an official.

The plan for the development of a city cluster in the greater bay area, covering the majority of China's Cantonese-speaking regions, was forwarded to the National Development and Reform Commission at the end of June, said Wu Weibao, deputy head of Guangdong's development and reform commission.

"Compiled by the provincial development and reform commission and national think tanks, including the China Center for International Economic Exchanges (CCIEE), the plan sets the targets, development directions and major tasks for the area," Wu said.

The greater bay area will cover Hong Kong and Macao special administrative regions, and nine cities in Guangdong province including the first-tier cities of Guangzhou and Shenzhen.

"By 2020, the Guangdong-Hong Kong-Macao greater bay area is planned to become one of the world's top-level bay areas and form the basic framework for a world-class city cluster," said Zhang Xiaoqiang, CCIEE executive deputy head.

By 2030, the area is expected to have the highest GDP among all bay areas worldwide, and become an advanced manufacturing center, as well as an important global hub of innovation, finance, shipping and trade, he added.

"The area will see substantial improvement in its strength in global cooperation and competition, and ascend to the front of world-renowned city clusters by 2030," Zhang said.

The combined regional GDP of the greater bay area stood at 9.35 trillion yuan ($1.38 trillion) in 2016, compared with the GDP of the Chinese mainland at 74.41 trillion yuan last year.

Estimates show the regional GDP of the greater bay area will reach $4.62 trillion by 2030, surpassing Tokyo, New York and San Francisco bay areas to become the world No 1, Zhang said.

The plan includes major infrastructure projects, important development platforms, and major economic and trade cooperation that will have impacts beyond the area, he added.

The idea of creating a bay area was raised as early as 2009 in a research report for coordinated development of the city cluster in the greater Pearl River Delta region, jointly released by local governments of the three regions.

In 2015, building the Guangdong-Hong Kong-Macao greater bay area was included in a report on vision and actions to jointly build the Belt and Road Initiative.

The area's development entered a fast track this year after the annual government work report made it clear that China will draw up a plan for the greater bay area.

"(The country will) give full play to the distinctive strengths of Hong Kong and Macao and elevate their positions and roles in China's economic development and opening up," the report said.

A framework agreement on the development of the greater bay area was signed by central and local officials on July 1, the 20th anniversary of Hong Kong's return to the motherland.

Under the agreement, Guangdong, Hong Kong and Macao will improve collaboration mechanisms and facilitate win-win cooperation to build a world-class bay area and city cluster.