I was amazed as well but I didn't find any proof. He had some comments on free trade concerning NAFTA. However, he insulted Justin Trudeau for doing "such a terrible job, he should be ashamed to call himself the President of Canada", but this tweet was on August 23rd, 2017 - during his presidency.
If you find any proof I failed to see, I will add Canada naturally.
The North Korean issue became relevant in the period between his election and inauguration. And thanks for mentioning the spelling mistakes, I corrected them.
If you find any proof I failed to see, I will add Canada naturally.