OTTAWA — U.S. President Donald Trump threatened Tuesday to rename Lake Ontario “Lake America,” saying the United States no longer expects to conduct much business with Canada’s most populous province.The threat followed Ontario Premier Doug Ford’s warning that Canada could triple prices on oil and critical minerals or cut off electricity exports to the United States as the cross-border trade war escalates..“The United States is giving serious consideration to changing the name of Lake Ontario to Lake America in that we don’t expect to doing much business with Ontario any longer,” Trump wrote on Truth Social Tuesday morning.“Thank you for your attention to this matter!”Trump did not announce an executive order or provide details about how the proposed change would be implemented.Lake Ontario straddles the international boundary, with Ontario on its northern shore and New York state to the south..The United States could adopt a different name for use by its own federal agencies, as Trump previously did by ordering the Gulf of Mexico identified as the “Gulf of America” in American government documents.Washington cannot compel Canada, Ontario or international organizations to adopt the same name.The Ontario Geographic Names Board makes recommendations concerning official geographical names within the province.Trump’s post followed a war of words with Ford on Monday.As previously reported, Ford said Canada should consider charging the United States three times as much for Canadian oil, potash, uranium, metals and rare-earth minerals.The premier also said Ontario could increase the price of electricity exported to the United States or stop shipments altogether.“We power 1.5 million homes and businesses,” Ford said. “Everything’s on the table. I’ll do whatever it takes.”Ford reserved his bluntest response for Trump personally.“I have a lot of real estate on my ass, so he has a lot of room to kiss my ass,” he said.Trump had previously called Ford a “flunky” and compared him unfavourably with his late brother, former Toronto mayor Rob Ford.The dispute intensified after Canada-U.S. trade negotiations collapsed Friday and Washington imposed 50% tariffs on roughly $28 billion worth of Canadian goods.Prime Minister Mark Carney has announced dollar-for-dollar retaliatory tariffs beginning September 8.On Monday, Trump separately threatened to increase tariffs on Canadian cars, trucks, automotive parts and steel to 50% beginning January 1, 2027.Lake Ontario’s established name predates the province, which adopted the name Ontario at Confederation in 1867. The name is derived from a Wendat word commonly translated as “great lake” or “beautiful water.”