US President Donald Trump signed an executive order on Thursday directing the federal government to rename Lake Ontario as Lake America, marking a new chapter in his administration's increasingly strained relationship with Canada.The order calls for the name change to take effect immediately and directs the Department of the Interior, under Secretary Doug Burgum, to carry out the change across relevant federal government agencies and systems, according to earlier reports.Lake Ontario, one of North America's five Great Lakes, sits along the border between the US state of New York and Canada's province of Ontario.— WhiteHouse (@WhiteHouse) The move comes only days after Trump publicly floated the idea of replacing the name Lake Ontario with Lake America, as trade tensions between Washington and Ottawa continued to intensify.A name change involving two countriesLake Ontario is the easternmost of the five Great Lakes and forms part of the boundary between the US state of New York and the Canadian province of Ontario. That shared geography could make Trump's latest renaming effort more complicated than simply changing a name on U.S. government documents.The United States and Canada jointly manage aspects of the waterway, while each country has authority over its respective portions of the lakebed and shoreline.The executive order can direct US federal agencies to adopt the name Lake America, but it cannot compel Canada, international organisations or private entities outside the federal government to use the new designation.Similar questions emerged after Trump ordered the US government to rename the Gulf of Mexico as the Gulf of America in 2025. That change applied to U.S. federal government usage, but Mexico and other countries continued to use the original name.Trade tensions provide the backdropTrump's decision comes after U.S.-Canada trade negotiations collapsed last week following three days of intensive talks.Both governments have blamed the other for the breakdown, adding another layer of tension to an already strained relationship between the neighbouring allies.The dispute has involved disagreements over tariffs and trade policy, with both Washington and Ottawa accusing the other side of making unreasonable demands.Trump had initially framed the potential name change as part of his increasingly hostile rhetoric toward Ontario and Canada amid the trade conflict.