Indonesian President Joko Widodo broke ground Thursday on the country's first ever bullet train line, heralding the project as a symbol of "major cooperation" with China.

The controversial $5.6 billion project sparked a fierce bidding war between China and Japan as the two Asian powerhouses jostle to build key infrastructure projects in Indonesia and the wider region.

Widodo kicked off the first construction phase at a tea plantation in West Java, where one of the stations along the line will be situated.

"Send my regards to (Chinese) President Xi Jinping," Widodo said at the event, attended by Chinese officials.

"This is a (sign of) major cooperation between Indonesia and China," he added, calling for the two trading partners to further expanded ties in other industries.

The bullet train should in theory be able to travel up to 350 kilometres an hour (220 miles per hour) between the sprawling capital Jakarta and the mountain-fringed city of Bandung, about 160 kilometres (100 miles) away.

It is a key project for Widodo, who has pledged to overhaul the archipelago's rickety infrastructure in a bid to attract investors and boost growth in Southeast Asia's largest economy, which last year dipped below five percent.

Last year Jakarta asked for proposals from investors for the ambitious project, with China and Japan bidding so intensely a senior minister likened Indonesia to a pretty girl being courted by many admirers.

After a chaotic bidding process, China was awarded the contract -- infuriating Japan, which was long expected to build the track given its high-speed rail expertise.

Indonesia lacks a mass-transport system, forcing its increasingly affluent 250 million people to rely heavily on private transport, resulting in grinding traffic in the biggest cities.

Widodo said he hoped the high-speed railway would spur demand for future public transport alternatives in other parts of Indonesia, as well as speed up the movement of people and goods between cities, helping economic growth.

Construction of the line is expected to finish by 2018, and it should be operational the following year.