Yes, International students are funded during their PhD by US universities.
Evidence: I received a fully funded PhD admit last week for the fall 14 semester:). It’s a graduate assistantship and includes a monthly stipend, 100% tuition waiver and health insurance.
I think, getting a funded admit mainly depends on the program. Some programs offer full funding to all admitted students, other programs may fund only some of the new admits while there are programs which offer only fellowships to new students (fellowships may not cover all costs and are offered to very few candidates in the whole university).
So, ask around before choosing programs. Choosing the right program may increase the chances of getting funded admits.
But there’s a catch, if u only apply to programs offering funding to all admitted students, then u might face an ALL OR NONE situation. If your application falls short compared to the other applicants, you might end up with no admits. So, choose some of the other types of programs, too.
I hope this helps.