Canadian Prime Minister Mark Carney rejected President Donald Trump’s order to call Lake Ontario “Lake America” for US federal purposes, saying Canada would continue using its longstanding name. The dispute adds a symbolic dimension to already strained US–Canada relations, particularly amid a broader trade conflict, but the US order cannot oblige Canada or international bodies to adopt the new designation.

Carney said the name derives from the Wendat word “Ontari’io” and is more than 400 years old, predating both Canadian Confederation and US independence. Trump signed the order on Thursday, directing the Interior Department to update the federal Geographic Names Information System; Lake Ontario forms part of the boundary between New York and Ontario and has been governed jointly under the 1909 Boundary Waters Treaty.