BEIJING - China is developing new bullet trains with a speed up to 400 kph, said a leading figure in the country's high-speed railway technology development.

Ding Rongjun, an academician of the Chinese Academy of Engineering, said that China was also researching the next generation magnetic-levitation train with a top speed of 600 kph, at a press conference Monday.

"We are now focusing on how to link TV signals to the trains so that passengers will be able to enjoy films on window-turned screens," Ding said.

A permanent magnet drive system has been added to trains and is undergoing assessment, he said, adding that automatic and unmanned drive technology will be used in the future.

The maximum speed of China's bullet trains rose to 350 kph, when the Fuxing (Rejuvenation) bullet trains started operation between Beijing and Shanghai on Sept 21, 2017.

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