It’s hard to say, and it really depends on how bad the score is. If you find you are seldom approved for cards in Canada, then you may want to consider other avenues.  If you have a card membership with American Express in your international country, it may be wise to instead apply via Amex US Global Transfer where only your history with Amex will be considered in your creditworthiness assessment.  Otherwise, you could consider getting an ITIN and applying for a secured card to get started.