US electric vehicle maker Tesla is "very close" to achieving level 5 autonomous driving technology, chief executive Elon Musk said on Thursday, referring to the capability to navigate roads without any driver input. "I'm extremely confident that level 5 or essentially complete autonomy will happen and I think will happen very quickly," Mr Musk said in remarks made via a video message at the opening of Shanghai's annual World Artificial Intelligence Conference. "I remain confident that we will have the basic functionality for level 5 autonomy complete this year," he added. Automakers and tech companies including Alphabet's Waymo and Uber are investing billions in the autonomous driving industry. However, industry insiders have said it would take time for the technology to be ready and for the public to trust autonomous vehicles fully. The California-based automaker currently builds cars with an Autopilot driver-assistance system. Tesla is also developing new heat-projection or cooling systems to enable more advanced computers in cars, Mr Musk said. Industry data showed Tesla sold nearly 15,000 China-made Model 3 sedans last month. Tesla has become the highest-valued automaker as its shares surged to record highs and its market capitalisation overtook that of former front-runner Toyota.