White House officials are discussing the possible deployment of troops to the Canadian border.
The potential move is driven by US fears about the integrity of the border during the coronavirus pandemic and fears that people carrying the virus may enter the country illegally.
Canadian Prime Minister Justin Trudeau confirmed that he is aware of the discussions during his daily briefing.
Deputy Prime Minister Chrystia Freeland told reporters that Canadian ministers and diplomats have made it clear that this is not a plan Canada supports.
“Canada is strongly opposed to this US proposal and we’ve made that very clear to our US counterparts,” she said. Ms Freeland confirmed that Canadian officials learned of the proposal a few days ago.
In his press conference, Mr Trudeau said “Canada and the US have the longest unmilitarised border in the world, and it is very much in both of our interests for it to remain that way.”
The possibility of troops being stationed along the US side of the border was first reported by Canada's Global News, which cited sources as saying that they would be based approximately 15-20 miles from the border and would rely on remote sensors to pick up on border crossings.
Information would then be shared with Customs and Border Patrol agents who would take appropriate action. It is thought there would be no more than 1,000 troops involved.
The border between the US and Canada has been closed to all but essential traffic since midnight on 21 March.