There have been numerous rumors about Apple’s plans to develop self-driving cars, however, CEO Tim Cook clarified to Bloomberg his company is working on an autonomous car system.

Apple has been secretive about its autonomous driving program called Project Titan. During Apple’s Worldwide Developers Conference on June 5, Cook admitted the company is working on self-driving technology.

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"We're focusing on autonomous systems," Cook told Bloomberg. "It's a core technology that we view as very important."

Cook’s comments come after the company introduced its home assistant, HomePod. The CEO then went on to talk about the importance of artificial intelligence.

"We sort of see it as the mother of all AI [artificial intelligence] projects," he said. "It's probably one of the most difficult AI projects actually to work on."

What Is Project Titan?

Previous reports have pointed to moves the company was making on the project. In April, Apple was given the green light for testing self-driving cars in California, the state’s Department of Motor Vehicles’ website revealed. Apple’s DMV application includes a walkthrough of the Development Platform Specific Training and details about an autonomous-vehicle system called Apple Automated System. In the documents, an Apple official said the "development platform uses hardware and software to monitor surrounding objects and events." The application also included a copy of the testing process Apple used to certify six drivers who will pilot three modified 2015 Lexus RX450h SUVs.

Apple reportedly hired three former NASA engineers for Project Titan, also in April. The engineers, who previously worked on detection of 3D objects and motion planning algorithms, were supposed to test Apple's self-driving car software.

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A report in March said the iPhone maker was quietly operating a research lab in Switzerland and had hired computer visions and robotics researchers, possibly for self-driving technology.

Cook would not say last week if Apple will end up developing its own self-driving car in the future.

"We’ll see where it takes us," Cook told Bloomberg. "We’re not really saying from a product point of view what we will do."

Apple vs. Samsung

Apple rival Samsung seems to be going in the same direction. The company was granted permission by South Korea’s Ministry of Land, Infrastructure and Transport last month to test self-driving cars. Samsung, which had previously entered the auto business but failed, said it was not looking into developing autonomous cars.

“The pilot run is being carried out for software and solution development for an autonomous car, nothing more,” a Samsung official told the Korea Herald at the time. “The test has nothing to do with devices development, but [is being carried out] to test software and algorithm under development by Samsung.”

Other companies have been experimenting with self-driving technology. Uber is testing its autonomous cars in various U.S. cities. Meanwhile, Google created its self-driving car unit Waymo last year. The company, which is in a legal battle with Uber, launched a self-driving taxi program in Phoenix in April and is also testing driverless truck technology.