DETROIT (AP) — Tesla Inc. CEO Elon Musk says the company plans to unveil an electric semi-truck in September.

Musk tweeted the announcement Thursday. He offered no other details about the semi, such as whether it will be equipped with Tesla's partially self-driving Autopilot mode.

Musk also said the company plans to unveil a pickup truck in 18 to 24 months.

Tesla currently sells two electric vehicles, the Model S sedan and Model X SUV. Its lower-cost Model 3 electric car is due out by the end of this year.

But Musk revealed last summer that the Palo Alto, California-based company is working on several more vehicles, including the semi and a minibus.

Tesla shares rose nearly 3 percent in late trading Thursday in response to Musk's tweet.