I am a Canadian citizen and now work in the U.S. under a TN Visa I bought a house just across the border in Canada. The mortgage is with a bank in Canada, and they do not issue a Form 1098. Can I deduct the mortgage interest and property taxes on my U.S. tax return? If, so, what documentation would I need?

Yes, you can deduct that interest.

You just need to identify to whom you are making the interest payments.