WASHINGTON - American automaker and energy storage company Tesla will build an all-electric pickup soon after it begins building the Model Y SUV, which is expected to go into production in mid-2019, Tesla CEO Elon Musk said Tuesday.

"I promise that we will make a pickup truck right after Model Y. Have had the core design/engineering elements in my mind for almost 5 years. Am dying to build it," Musk said via Twitter.

The Model Y, which will be built on the same platform as the Model 3 sedan, is expected to go into production in mid-2019.

The idea of building electric pick-up trucks was first announced last July. Adding a pickup truck to its lineup would make Tesla the first full-line electric automaker, making it better compete with traditional internal combustion engine brands like BMW and Toyota.

Musk also said via Twitter that the pick-up truck would likely be a little larger than the current bestselling model Ford F150 pick-up. He said the truck would have a "gamechanging" feature, but he didn't reveal details.