The brief has been signed by several tech giants, including Apple, Google, Facebook and Microsoft, and says Trump's ban "inflicts significant harm on American business." According to the companies, the travel ban harms their employees and customers and limits their growth.
Musk has come under fire in recent days for his affiliation with Trump – the Tesla and SpaceX CEO is currently part of two advisory councils under the President. He defended his connection to Trump through several tweets, saying he used a council meeting to discuss the immigration ban and climate change.
"I understand the perspective of those who object to my attending this meeting, but I believe at this time that engaging on critical issues will on balance serve the greater good," he wrote in a note posted on Twitter.