Tesla is "very close" to achieving level 5 autonomous driving technology, chief executive Elon Musk was quoted as saying on Thursday.

"I'm extremely confident that level 5 or essentially complete autonomy will happen and I think will happen very quickly," Reuters quoted Musk saying, in remarks made via a video message, at the opening of Shanghai's annual World Artificial Intelligence Conference (WAIC).

"I remain confident that we will have the basic functionality for level 5 autonomy complete this year."

Industry insiders have said it would take time for the technology to get ready and public to trust autonomous vehicles fully, the news agency report noted.

Tesla currently builds cars with an Autopilot driver assistance system.

Musk said Tesla was also developing new heat projection or cooling systems to enable more advanced computers in cars.

Industry data showed Tesla sold nearly 15,000 China-made Model 3 sedans last month, Reuters said.

Tesla recently became the highest-valued automaker as its shares surged to record highs and its market capitalisation overtook that of former front runner Toyota Motor.