US President Donald Trump has signed an executive order seeking to rename Lake Ontario as “Lake America”, escalating an already tense dispute with Canada over trade and national sovereignty.
Trump announced the move on Thursday, saying the name change was “official, effective immediately”. He also said his administration had submitted the necessary paperwork to make the change.
Under the executive order, the US Department of the Interior has 30 days to update the proposed name in the Geographic Names Information Service, the official US repository for domestic geographic names.
The announcement comes after trade negotiations between Washington and Ottawa broke down late last week. The US subsequently imposed new 50% tariffs on about US$20 billion (C$28 billion) worth of Canadian goods, while Canada is preparing matching “dollar-for-dollar” retaliatory tariffs next month.
Trump has repeatedly raised the idea of renaming the lake on social media during the trade dispute, despite Lake Ontario being one of the five Great Lakes shared by the United States and Canada.
Canadian Prime Minister Mark Carney rejected the proposed change, pointing out that the name Lake Ontario has been used for more than 400 years and predates both Canadian Confederation and the US Declaration of Independence.
“We know that the United States is changing. Their trade relations, their foreign policy, their national monuments, their hydronyms,” Carney wrote on social media. “Canadian women and men also know that things must be called by their name, and this lake is called Lake Ontario – today and forever.”
Ontario Premier Doug Ford also dismissed Trump’s move, saying Canadians and the rest of the world would continue to call it Lake Ontario. Nova Scotia Premier Tim Houston similarly described the proposal as “some real foolishness”, while Industry Minister Melanie Joly said Canada would continue using its existing name.
Lake Ontario is the smallest of the five Great Lakes and sits along the border between Ontario and New York state. Four of the lakes – Ontario, Huron, Michigan and Erie – have names originating from Indigenous languages, while Lake Superior derives its name from an anglicised French term.
The proposed renaming follows a similar move by Trump after he returned to the White House in 2025, when he ordered the Gulf of Mexico to be referred to as the “Gulf of America” in the United States.
Mexico rejected that change, arguing that one country could not unilaterally rename a shared international body of water. The issue also resulted in a legal dispute involving Google after the technology company changed the name displayed on its mapping service according to the user’s location.
Google Maps users in the US see “Gulf of America”, while users in Mexico see “Gulf of Mexico”. In other countries, the service displays “Gulf of Mexico (Gulf of America)”.
The earlier Gulf of Mexico dispute also saw the White House bar Associated Press reporters from presidential events after the news agency declined to adopt “Gulf of America” in its reporting. The AP subsequently sued the Trump administration, with the legal dispute still ongoing.
There is no universally recognised international authority responsible for determining the names of international waters. While the US president has broad authority over how geographical features are officially recognised by the US government, other countries are not required to accept such changes.
The latest proposal has also drawn criticism from US politicians. Democratic Congresswoman Debbie Dingell of Michigan said she would introduce legislation seeking to overturn the name change, describing Trump’s order as “idiotic”.
She argued that the Great Lakes were a shared treasure protected by generations of Americans and Canadians.
Other Democratic lawmakers mocked the move and urged the administration to focus on resolving the trade dispute instead. Wisconsin’s governor even jokingly declared that he had renamed Lake Michigan “Lake Wisconsin” in a social media post.
New York Governor Kathy Hochul, whose state is the only US state bordering Lake Ontario, said New York would not be adopting the proposed “Lake America” name.
Trump, meanwhile, said the move was not intended as a direct message to Canada but linked it to his long-standing criticism of the country’s trade relationship with the US.
He also joked that after renaming a gulf and a lake, his administration might eventually consider changing the names of the Atlantic or Pacific oceans.
Despite the increasingly heated rhetoric, there were signs on Thursday that trade negotiations between the two countries could eventually resume. Canadian US Trade Minister Dominic LeBlanc said Washington had withdrawn some demands concerning French-language labelling and had confirmed that measures supporting the French language and Canadian culture would not be targeted by future US trade actions.
LeBlanc said further clarification from Washington on other issues could create an opportunity for a mutually beneficial agreement that respects Canadian sovereignty.
The trade negotiations had collapsed after both sides accused the other of introducing last-minute demands to a tentative agreement, leaving relations between the neighbouring countries at one of their lowest points in recent years.
US Interior Secretary Doug Burgum welcomed Trump’s latest order, saying the department was ready to implement the change and arguing that American places and waters should reflect the country’s identity and economic importance.
