The Buy America Act does not affect Canada...
"Buy American requirements also do not apply to Canada for U.S. federal purchases covered by the revised World Trade Organization Agreement on Government Procurement (WTO GPA), to which Canada, the U.S. and 46 other countries are Parties. When bidding on U.S. federal procurements covered by these agreements, Canadian suppliers benefit from the same treatment as American suppliers. There are also exceptions in the Buy American Act for the acquisition of commercially available off-the-shelf (COTS) items."