Is it Possible to Apply Just for PhD Research and get Assistantship?

[academicus]

Hello, 
I have started to write my thesis in my  country (Turkey). But it is impossible for me to do my research here. Because of my research subject I have to spend some time abroad. So I have found some academics working in the same field with me (From USA) and sent my proposal to them. Still waiting for answer. What I want to ask is:

1. Is it possible to just go for research and be an assistant or should I apply as a Phd student for that? 

2. Will schools want me to get same exams  required for Phd applications?

If you any ideas and share with me I would be really grateful...

 

Edited May 12, 2018 by academicus

[qocha_geog]

If I' understanding your situation correctly, you're currently a PhD student in Turkey? Rather than applying for programs at the American universities have you looked to see if any of them have visiting graduate student programs.  Or obviously difficult to get but this seems like the exact reason Fulbright Fellowships exist, to fund people to do short time research in the US.