Trump signs executive order renaming 370-year-old Lake Ontario ‘Lake America’ as Canada trade tensions rise.

US President Donald Trump has signed an executive order renaming Lake Ontario “Lake America”, taking the US-Canada trade war into unusual territoryLake Ontario is one of the five Great Lakes and straddles the Canada-US border, with Ontario to its north and New York to its south.

The Great Lakes — Huron, Ontario, Michigan, Erie and Superior — are a chain of five freshwater lakes that hold roughly one-fifth of the world’s surface freshwater.

Although the first known appearance of “Lake Ontario” on a map dates to 1656 — predating both the US and Canada — historians say the name had been in local use long before then.But on Thursday, Trump sought to change history.

“This is official, effective immediately,” Trump said after signing the order in the Oval Office.

The president said he had “filed all the necessary papers, documents, everything else” for the name change and “notified all of the various people that we have to notify”.

The order said that with “the deepest parts of the Lake’s waters lying within United States territory, the United States claims most of the Lake’s volume” and that the lake has “long been an integral asset to American exploration, settlement, commerce, and defense”.Geographical names are not controlled by one worldwide authority. As such, it is uncertain whether Trump’s order will take effect outside the US.

Lake Ontario is recognised as a post‑glacial lake formed from Lake Iroquois about 11,400 years ago.

By the mid-1700s — before the American Revolution and the eventual creation of Canada and the United States — Lake Ontario had emerged as the name that stuck.The name Ontario is thought to be of Iroquoian origin, meaning “beautiful lake” or “sparkling water,” according to the Canadian encyclopaedia. Some historians say it also means “vast body of water”.

By about 1641 in French missionary records referred to the lake as Lake Ontario. The province, created at Confederation in 1867, later took its name from the lake.

Earlier in the week, before Trump’s order to rename the lake was signed, Mélanie Joly, Canadian industry minister said: “We’ll always call it Lake Ontario”.The name change is reminiscent of Trump’s move last year to rename the Gulf of Mexico to the Gulf of America.

“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,” Trump said, referring to the bodies of water on either side of the US coastline.

Trump’s move comes after a week of back-and-forth between the two countries following the breakdown of trade talks late Friday and the imposition of 50 percent tariffs on billions of dollars’ worth of Canadian exports.