US President Donald Trump has signed an executive order directing that Lake Ontario be officially referred to as "Lake America" within the United States, a move announced amid escalating trade tensions with Canada.

The order, signed Thursday in the Oval Office, instructs Interior Secretary Doug Burgum to update the lake's name in the US Geographic Names Information System and to remove references to Lake Ontario from department and agency maps, contracts, and other documents, as reported by smh.com.au and The Times of India.

According to France 24, Trump signed the order while sitting at the Resolute Desk, with a large map of the Great Lakes displayed behind him showing "Lake America" in large red letters over Lake Ontario. A cardboard sign reading "Making the Great Lakes Even Greater" was also present, as noted by smh.com.au.

The renaming applies only to how US authorities officially identify the body of water; Trump has no power to make Canada adopt the name, as reported by The Times of India and France 24.

Trade dispute context

The announcement comes after trade talks between the US and Canada collapsed late last week, according to BBC. The US subsequently imposed new 50% tariffs on $20bn (C$28bn) worth of Canadian goods, and Canada has said it will implement "dollar for dollar" counter tariffs next month, as reported by BBC and France 24.

France 24 reported that Canada responded this week with retaliatory tariffs on $20 billion worth of American goods, including steel, dairy products, appliances, and farm equipment.

Speaking to reporters, Trump criticized Canada's trade practices, saying, "Canada has been ripping us off for a long time on trade," as quoted by smh.com.au. He also described Canadian government officials as "nasty people" and "entitled," according to smh.com.au and The Times of India.

Trump said the move was not a direct message to Canada, but that America's northern neighbour "has been ripping us off for a long time on trade," as reported by BBC. He added that he had been thinking about renaming the lake "for a long time."

According to smh.com.au, a Trump aide in the Oval Office said: "This is a lake that has most of its volume in the United States. The deepest parts of the lakes are in United States territory. So, this will reflect that this is an American lake."

Trump also suggested the renaming effort may continue, saying: "So if you think about it, we have a gulf and we have a lake... Now, all we need is an ocean. So maybe we'll have to change the name of the Atlantic and or the Pacific," as quoted by BBC and France 24.

Canadian response

Canadian Prime Minister Mark Carney pushed back against the order, citing the lake's Indigenous origins. In a social media post, Carney noted that the name Lake Ontario can be traced back more than 400 years, predating both the Canadian Confederation and the US Declaration of Independence, as reported by BBC.

"We know that the United States is changing. Their trade relations, their foreign policy, their national monuments, their hydronyms," Carney wrote, according to BBC and France 24. "Canadian women and men also know that things must be called by their name, and this lake is called Lake Ontario – today and forever."

Other Canadian officials also dismissed the move. Nova Scotia Premier Tim Houston wrote on social media: "We're into some real foolishness now. It's Lake Ontario, buddy," as reported by France 24. Ontario Premier Doug Ford brushed aside the prospect as "a lot of rhetoric," according to the same outlet.

Canadian US trade minister Dominic LeBlanc said in a post on X that the US had withdrawn some of its demands around labelling requirements in French, and expressed hope for further constructive clarifications, as reported by BBC.

Name origins and precedent

The name Ontario has Indigenous origins. According to France 24 and The Times of India, it comes from the Huron people's word "oniatarí:io," meaning "lake of shining waters." smh.com.au reports that Carney noted the name "Ontari'io" comes from the Wendat people and means "the lake is beautiful, the lake is big," and that it predates European settlement. The province of Ontario, founded in 1867, took its name from the lake, as noted by France 24 and The Times of India.

The move follows Trump's earlier decision to rename the Gulf of Mexico as the "Gulf of America" for US government use, as reported by BBC, France 24, smh.com.au, and The Times of India. In that case, Mexico rejected the name change, arguing a single country cannot rename a shared body of international water, according to BBC. Google Maps shows "Gulf of America" to US users and "Gulf of Mexico" to Mexican users, with other countries seeing "Gulf of Mexico (Gulf of America)", as reported by BBC.

There is no universally recognized international body setting the names of international waters, as noted by BBC and The Times of India. The International Hydrographic Organization, whose members include the US and Canada, helps ensure that seas, oceans and navigable waters are surveyed and charted consistently and is responsible for naming some waterways, according to The Times of India.

Lake Ontario is one of the five Great Lakes that straddle both countries, as reported by BBC. The international border runs through the lake, with New York State to its south and the Canadian province of Ontario to its north, according to The Times of India. The lake separates Buffalo from Toronto, Canada's largest city, and Ontario is Canada's most populous province and the biggest export market for more than a dozen US states, as reported by The Times of India.

Trump has repeatedly suggested that Canada should become the 51st US state, despite the two countries being long-standing allies, as reported by France 24 and The Times of India. The name change request comes amid a trade dispute that has seen US-Canada relations fall to new lows, according to BBC.