One has to have the puppy registered in its country of origin first. Then one would fill out a Foreign Born Registration from the AKC. It would need to be submitted along with the fee, and the 3 generation pedigree from the country of origin, a copy of its original registration and front and side view pictures.
Of course, AKC will only register puppies from nationally recognized kennel clubs like the Canadian KC. And those puppies must not be on a non-breeding contract from Canada, if we are talking about Canada.
No registrations country to country are interchangeable.
If you go to the AKC website and do a search (because I can't remember where the instructions are) for AKC registration, foreign dogs it will get you to a location with complete instructions. In some cases the instructions for one registry/country are slightly different than those for other registries/countries.
Not all foreign registries have reciprocal agreements with the AKC and the AKC does not recognize some of them so you need to check individually.
A Canadian dog registered with the CKC is one of the easiest registrations to have the dog registered with the AKC