Tesla CEO Elon Musk has launched a new political party in the United States, declaring the formation of the “America Party” on Saturday. The move follows Musk’s fallout with President Donald Trump over a sweeping tax and spending bill that Musk criticized for deepening the nation’s fiscal woes.

President Donald Trump assailed Elon Musk on Sunday night, describing him as “off the rails” after Musk said he was creating a new political party amid an ongoing rift with the president.