Indonesia has launched Southeast Asia's first high-speed railway, a joint venture with China that President Joko Widodo hailed as "a symbol of our modernisation".

He declared the official operation of the Jakarta-Bandung High-Speed Railway at Halim Station in Jakarta on Monday morning.

With a top speed of 350 kilometres per hour, the bullet train "Whoosh" can get between the capital and Bandung in 45 minutes. The 140km journey would previously have taken about three hours by train.

"The Jakarta-Bandung high-speed train marks our efficient, friendly and integrated mass transportation system," Widodo said.

"It is a symbol of our modernisation in the public transport, seamlessly connecting with other modes of transportation."

Representatives from the Chinese Embassy in Indonesia, China Railway International Group, and PT Kereta Cepat Indonesia-China – a joint venture consortium between Chinese and Indonesian firms that builds and runs the project – attended the ceremony.

The US$7.3 billion high-speed line is part of the Belt and Road Initiative.

Last month, Premier Li Qiang joined a senior Indonesian minister, Luhut Pandjaitan, on a ride aboard the train during his Jakarta visit for summits with Southeast Asian leaders. (Agencies)