Trump said the decree was effective immediately as he signed the order to rename it Lake America.

While he has broad discretion over how the US recognises landmarks, other countries are not required to follow. Canadian officials have dismissed Trump’s move.

On Saturday, Trump also posted several AI-generated videos on social media, with one showing him kicking over a Lake Ontario sign and replacing it with one that says: “Welcome to Lake America.”

Another video depicted a flock of Canada geese sporting the US president’s hair and holding rifles as they patrolled the shoreline of a newly named Lake America.

Ford said Trump’s renaming of the lake was because he “didn’t like Ontario and Canada standing up for ourselves”.

Standing in front of the newly unveiled Lake Ontario sign, Ford added: “Just in case President Trump or anyone else forgets, we’ve set up this sign to remind them, it’s Lake Ontario, now and forever.”

It echoes Canadian Prime Minister Mark Carney’s previous response to the row, insisting “things must be called by their name, and this lake is called Lake Ontario – today and forever”.