The term "CNA" (certified nursing assistant) gets bandied around a lot, but in many areas, you don't have to actually be "certified" to be a nursing assistant. It's not rocket science to be entry level anyway, and many places prefer to train you themselves. Besides, there's nothing that you learn in the course of becoming a "certified" NA that you don't already know from nursing school, and any employer will know that. So if I were you, I would try to get a job as a nursing assistant in an ICU or surgical area. Let them know your situation, that when your paperwork comes through and whatever else needs to happen for you to become an RN that that's what you want to do, and in the meantime you'd like to work as an aide. It may be the case that they don't even have an RN opening right now but they anticipate that they will in a few months. If so, your foot's in the door, and they have the benefit of a new RN who knows the ropes of the unit. And if it turns out that they don't have a position when you're ready, then at least you've been honest with them.
If you go the "Starbuck" route, it's not a problem if you stay for a few months and then quit for something better. It happens *all* *the* *time*, it's part of doing business for retails companies. You might not want to highlight the fact that you actively have plans to only stay for a little while on your application/interview, but you can still be honest. You're in the process of getting credentials transferred from another country, who knows how long that could take or what problems you could face with it, and in the meantime, you'd like to make a little money and have some fun at Starbucks (or wherever) - I don't think that's anything that would turn off a hiring manager, it's par for the course.
Even if you got a nursing assistant position in a unit where you knew you weren't planning on staying, I know some people stay in those jobs long-term but most are on their way somewhere else. Finally, keep in mind that for a new nurse, it's very hard to get a job in a specialty area these days. You may *want* to start off in ICU or the OR, but you are going to have fierce competition for very few new-grad openings. So that NA job in a unit where you didn't think you wanted to stay may turn out to be your best bet of getting an RN job anyway!