Washington. US President Donald Trump stepped up an escalating feud with Canada on Thursday, ordering that Lake Ontario – a body of water shared by both countries – be renamed "Lake America."

Trump signed an executive order on the name change at the White House, further trolling Canada as the North American neighbors plunge deeper into a trade war.

"We're going to be changing the name of Lake Ontario effective immediately to Lake America," Trump told reporters in the Oval Office.

Behind Trump's desk were two maps of the US-Canada border -- one with the words "Lake America" in red over the lake, and the other with the header "Making the Great Lakes Even Greater."

Asked why he was targeting an ally for punishment instead of America's adversaries, Trump replied: "The Canadian officials have treated us very badly. They're nasty people."

"People, oftentimes, they'll ask me who's the worst to deal with on trade? And I said that's easy. Canada. They are the worst to trade with," the 80-year-old Republican added.

Canada did not immediately comment but is unlikely to accept the renaming of Lake Ontario, the smallest of the five Great Lakes by surface area, which borders Canada's Ontario province and New York state.

US-Canada trade talks collapsed at the eleventh hour last week, with Trump's tariffs taking effect on Saturday.

Canada responded with tit-for-tat tariffs on Tuesday, with Prime Minister Mark Carney saying: "You're at war when you get attacked. We got attacked."

The same day, Trump announced that he was giving "serious consideration" to changing the name to Lake America.

He then posted a TikTok video late Wednesday saying that he intended to do so after all.

'Now All We Need Is an Ocean' 
The name change mirrors Trump's unilateral altering of the name of the Gulf of Mexico to the Gulf of America on his first day back in office in January 2025.

That change obliged the US federal government to refer to the gulf by the new designation, although Mexico has rejected any move to rename it and it lacks international recognition.

Trump said the name change was "something I've been thinking about for a long time, actually. As you know, we took something called the Gulf of Mexico, we changed it, and now it's very routinely the Gulf of America."

Trump also hinted at renaming oceans that border the United States.

"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. Maybe we'll change them both," he said.

While Lake Ontario shares its name with the Canadian province, the name itself is derived from the indigenous Huron word "Ontari'io," which means "great lake" or "beautiful water," according to the National Museum of the Great Lakes.

Toronto, Canada's largest city, sits on its northwestern shore.

During his second presidential term, Trump has irked a series of allies with his outlandish territorial claims, including that Canada should become the 51st US state.

Trump has also laid claim to Greenland, an autonomous territory of NATO ally Denmark, and talked about making Venezuela a state following the US capture of its leader Nicolas Maduro.

In recent days, he has also said that he will make the Strait of Hormuz between Iran and Oman a US territory, despite the fact that the war with Tehran remains ongoing.

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