USCG license

I am on the process for being a USA citizen ,I want to cross over my Marine Engineer Class 2 License to USCG license, for this is it essensial my Marine Engineer Class 3 and 2 license from UK(MCA) or it can be from any imo white listed country.
THNAKS IN ADVANCE

Maybe your second language english composition isnt all there, so here you go!