Uber on Monday informed employees, including some who had been previously approved for remote work, that it will require them to come to the office three days a week, CNBC has learned. 

"Even as the external environment remains dynamic, we're on solid footing, with a clear strategy and big plans," CEO Dara Khosrowshahi told employees in the memo, which was viewed by CNBC. "As we head into this next chapter, I want to emphasize that 'good' is not going to be good enough — we need to be great."