NANJING, Jan. 16 (Xinhua) -- Construction of a new high-speed railway started Tuesday in east China's Jiangsu Province as part of the north-south coastal railway network.

The 157-km line links Yancheng with Nantong and will take four years to complete at a cost of 26 billion yuan (4 billion U.S. dollars), according to the provincial railway office.

Upon completion, it will cut the travel time between the two cities from about two hours to 40 minutes.

"The Yancheng-Nantong railway will boost the integrated development of the coastal region of Jiangsu and the Yangtze River Delta region," said Lan Shaomin, vice governor of Jiangsu.

Jiangsu is one of China's most developed provinces, while the Yangtze River Delta is one of the country's economic powerhouses, covering Shanghai, and parts of Jiangsu, Zhejiang and Anhui provinces.

China's had 25,000 km of high-speed railway at the end of 2017, accounting for 66 percent of the world's total.