Just the wrong time to say it and get taken out of context
Crossing into Canada's air space seems a non-issue, it may just be as he said, the US will need to deploy more F-35
https://www.treaty-accord.gc.ca/text-texte.aspx?id=105060
Article II - Governing Principles, paragraphs e, f
"NORAD shall include such forces as are specifically made available to it by the Parties to fulfill its missions. The authority of Commander NORAD over those forces and resources is limited to operational control as defined in Article I, paragraph 2b.
Temporary reinforcement from one area to another, including the crossing of the international boundary, to meet operational requirements is within the authority of commanders having operational control."