CHONGQING, May 27 -- Vice Premier Zhang Gaoli said Wednesday that China will speed up major transport projects in hope of stabilizing economic growth.

The government will boost the development of railways, highways, waterways, airways and underground pipelines along the Yangtze River to build "a three-dimensional transport corridor."

The Yangtze runs west to east over 6,300 kilometers and is the longest river in Asia and the third longest in the world. It flows through 11 provinces and municipalities, and joins less developed inland provinces to prosperous Shanghai.

The construction of the "corridor" is part of the Yangtze River Economic Belt to enhance economic cooperation and integration among the regions along the river. The combined GDPof the 11 provinces and municipalities along the river amounted to 2.6 trillion yuan (415 billion U.S. dollars) last year, 41.2 percent of the national total.

"We will accelerate the construction of major transport projects and let investment stabilize economic growth," said the vice premier, who also stressed the significance of environmental protection during the process.

China's GDP grew 7.4 percent in 2014, the weakest annual expansion in 24 years. Its growth outperformed market expectation posting 7 percent in the first quarter, in line with the annual target set for the whole of 2015.

"There are signs of stabilization and improvements, but the downside pressure remains considerable. We must work hard to secure a sustainable and healthy growth," said Zhang.

In addition to the "corridor" construction along the Yangtze River, China is trying to scale up transport investment in a much broader scope.

The National Development and Reform Commission (NDRC), the country's top economic planner, issued a guideline Wednesday on transport infrastructure construction plans that will help Beijing, Tianjin and Hebei integration, connections with neighboring countries, along with transport infrastructure in central, western and northeastern regions.

"Transport infrastructure is a pillar of a country's economy and strategically important to social development," said the NDRC guideline.

"While China is facing arduous tasks of stabilizing GDP growth, overhauling economic structure, pushing ahead with reforms and improving people's livelihood, we should attach greater significance to transport investment in search of a leading power to underpin economic expansion," said the guideline.

In 2014, China spent 2.5 trillion yuan (407 billion U.S. dollars) on the construction of railways, highways and waterways.

In March, Premier Li Keqiangsaid that China will raise transport investment in 2015 and private investors are welcome to join in.

In addition to transport investment, the vice premier reiterated the government's commitment to entrepreneurship and innovation to foster new growth engines.

To that end, the vice premier promised further cuts to red tape, a lower market threshold and better government services.