This is complicated. In short, while in the U.S., you shouldn't get paid by your U.S. clients and the "work" you do should be along the lines of status meeting

This is complicated. In short, while in the U.S., you shouldn't get paid by your U.S. clients and the "work" you do should be along the lines of status meetings, not "productive" employment. Otherwise, you will need a work visa.