Absolutely. The safe third country agreement is an agreement between Canada and the United States. The agreement is essentially based on a principle. This principle, supported by the United Nations refugee agency, says that an asylum seeker should not engage in asylum shopping. They should claim asylum in the first safe country they land in. In essence, if an asylum seeker lands in Canada, they shouldn't claim asylum in the United States. The opposite is also true. If they first land in the United States, they shouldn't claim asylum in Canada.
Based on that principle, Canada and the United States entered into this agreement in 2004. The agreement says that we will enforce that principle. At the time the agreement was negotiated, the agreement was basically supposed to cover official ports of entry where Canadian and American officials can see the asylum seeker present themselves. The agreement, as it was entered into, covers that situation where people would present themselves at a port of entry and claim asylum. That agreement continues to be in place. When, for example, an asylum seeker comes from the United States and presents themselves at a Canadian port of entry, the safe third country agreement applies. They're told to go back to the United States to claim asylum there.
There are exceptions to the safe third country agreement. For example, if you have a blood relative or if you are an unaccompanied minor, then you can still make a claim in Canada. Essentially, however, as a broad principle, if you present yourself at a Canadian or an American port of entry, from either Canada or the United States, you're supposed to claim asylum in the country you came from.