US President Donald Trump has ordered Lake Ontario to be renamed “Lake America”, escalating tensions with Canada amid a worsening trade dispute between the two neighbours.
Trump announced the move on Thursday while signing an executive order at the White House, describing the name change as effective immediately.
“We’re going to be changing the name of Lake Ontario effective immediately to Lake America,” the 80-year-old Republican told journalists.
Asked by an AFP reporter why he was targeting an ally rather than America’s adversaries, Trump replied: “The Canadian officials have treated us very badly. They’re nasty people.”
The move was swiftly rejected by Canadian Prime Minister Mark Carney, who insisted the body of water would continue to be known as Lake Ontario.
“We know that America is changing,” Carney said in a post on X.
“Canadians also know that naming reality means calling it Lake Ontario — then, now and always.”
Trump’s latest naming row
Lake Ontario is the smallest by surface area of the five Great Lakes, which straddle the US-Canada border. It borders the Canadian province of Ontario and the US state of New York.
Trump’s order directs the US Department of the Interior to update references to the lake in the official geographical naming service within 30 days and ensure federal agencies use “Lake America”.
The order argues that the deepest part of the lake lies on the American side, meaning the United States “claims most of the Lake’s volume.”
The move echoes Trump’s unilateral decision in January 2025 to rename the Gulf of Mexico the “Gulf of America”, a change Mexico has also rejected.
Carney said the name Lake Ontario was about 400 years old and predated the formation of both the United States and Canada. He said it came from an Indigenous word meaning “the lake is beautiful, the lake is big.”
Trade tensions fuel dispute
Trump’s latest move comes after US-Canada trade talks collapsed at the last minute last week, leading the two longtime allies to impose retaliatory tariffs on each other.
Carney has adopted an increasingly confrontational stance towards Trump in recent days, declaring earlier this week that Ottawa was “at war” after being “attacked”.
The Canadian prime minister’s defiance has won praise from supporters at home.
Trump had signalled his intention to rename Lake Ontario on Tuesday, saying he was giving “serious consideration” to the idea. He later posted a TikTok video saying he would proceed.
In the Oval Office, maps displayed behind Trump’s desk showed the proposed name “Lake America”, alongside another map carrying the words “Making the Great Lakes Even Greater”.
Trump hints at renaming oceans
Trump also suggested that the Atlantic and Pacific oceans could eventually face similar treatment.
“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. Maybe we’ll change them both,” he said.
During his second presidential term, Trump has repeatedly angered allies with territorial claims, including his suggestion that Canada should become the 51st US state.
He has also claimed that the United States should acquire Greenland, an autonomous territory of NATO ally Denmark, and has discussed making Venezuela a US state following the US capture of its leader, Nicolas Maduro.
In recent days, Trump has also said he would make the Strait of Hormuz between Iran and Oman a US territory, despite the ongoing war with Tehran.
