Which is correct? North America Sales Meeting OR North American Sales Meeting?

I think both, with a nuance in meaning:

While North America Sales Meeting refers to a meeting taking place in
North America, North American Sales Meeting refers to a meeting that
belongs in North America. Thus, in the former I would expect to find
participants either from North America or from other places, while in
the latter I would assume that participants would be necessarily from
North America. Then, in practice, that doesn't need to be so strict,
but this is what either grammatical construction would suggest to me.
My two cents.

Although I agree with Guillermo's destinction, I still think "North
American Sales Meeting" is more appropriate in either case.

"North America Sales Meeting" does suggest what he describes, rather
also suggesting that there are or could be sales meetings in Europe or
Asia, but it would be rather unusual to refer to them as the "Europe"
or "Asia" Sales Meetings,  "European / Asian Sales Meeting" seeming
more normal and correct  - IMHO - using the adjective.  So I think the
adjective form "American" is also more correct.

It depends on whether the Vice President's title is "VP, Sales, North
America," or "VP, North American Sales."

North American Sales Meeting.