I'm not sure what's contemplated; obviously the U.S. could offer equipment lift; as well as whatever force is needed to grab control of the airport and other key facilities. I imagine they want us for the hold and maintain operation, but really don't know.
@kEiThZ might have heard something......
Or it could be all on the RCMP as you note.........with the problems that would entail;
but I can't imagine they are the right choice for any initial re-take strategic sites exercise.
But again, my insight here is more on the politics, not the strategic operation/logistics side.