According to the email, battery and powertrain production will take place at the Tesla Gigafactory in Nevada. Other work will most likely take place in other states, Musk said. Though, he didn’t reveal which states or when production will ramp up.

Earlier this year, Tesla said the Semi would arrive in 2021, not 2019 as originally planned. Ramping up production now could fit into that timeline.

Regardless of when or where the Tesla Semi is produced, it will likely face competition from Nikola, which plans to sell both electric and hydrogen big rigs. As Reuters points out, Musk’s email arrived shortly after Nikola Corp. began trading on the NASDAQ and saw its share prices more than double. There’s plenty of other electric-semi competition from companies like Daimler and Cummins, too.

Meanwhile, Tesla is also scouting new locations for Model Y and Cybertruck production. Tesla previously said it might build a third US factory in Austin or Tulsa. Musk has also threatened to move the company’s headquarters to Nevada or Texas.