BEIJING - China's high-speed rail tracks will hit 38,000 km by 2025, higher than 25,000 km registered by the end of 2017, the railway operator said.

The country's operating high-speed rail tracks accounted for 66.3 percent of the world's total by the end of 2017, said Lu Dongfu, general manager of China Railway Corporation.

The operator is aiming to build 4,000 km of new rail lines this year, 3,500 km of which will be high-speed rail tracks.

China's railway network will hit 175,000 km (about 108,740 miles) in length by 2025, compared with 127,000 km of operating tracks by the end of last year.

In 2017, a total of 3.04 billion passenger trips were made on railways, up 9.6 percent year on year. More than 56 percent of those trips were made on high-speed railways.

About 70 percent of rail tickets were sold online, while more than 70 percent of freight business were transacted online.

The maximum speed of China's bullet trains rises to 350 kilometers per hour, when Fuxing (Rejuvenation) bullet trains started operation between Beijing and Shanghai on September 21, 2017.

The Fuxing trains are a substantial upgrade on the previous bullet trains known as Hexie (Harmony). Entirely designed and manufactured in China, the Fuxing is more spacious and energy-efficient, with a longer service life and better reliability.

Last year, 3,600 cargo train trips were made between China and European cities, surpassing the previous six years combined, Lu said.