US President Donald Trump has signed an executive order seeking to rename Lake Ontario to Lake America.

The move comes after trade talks between the US and Canada collapsed late last week, and the US imposed new 50% tariffs on $20bn (C$28bn) worth of Canadian goods. Canada will implement “dollar for dollar” counter tariffs next month.

Trump has repeatedly posted threats about renaming the lake, one of the five Great Lakes that straddle both countries, on social media amid the trade dispute.

He said on Thursday the move was “official, effective immediately” and that his administration has “filed all the necessary papers, documents” to make the change.

Canadian Prime Minister Mark Carney noted the name Lake Ontario can be traced back more than 400 years, adding in a social media post on Thursday that preceded the formation of the 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,” he wrote. “Canadian women and men also know that things must be called by their name, and this lake is called Lake Ontario – today and forever.”

When Trump took the White House in 2025, he signed a similar order that changed the Gulf of Mexico to the Gulf of America. Mexico has rejected the name change, arguing a single country cannot rename a shared body of international water.

It also led to a legal dispute between Mexico and tech giant Google, which renamed the gulf in its maps application. , external

In that case, Google Maps users in the US see “Gulf of America”, while those in Mexico see the “Gulf of Mexico”. Those in other countries see the “Gulf of Mexico (Gulf of America)”.

The White House at the time also blocked Associated Press reporters from presidential events over the news agency’s refusal to adopt the name “Gulf of America” in its coverage. The AP sued the Trump administration in response, and that legal battle is ongoing.