In an unprecedented move, U.S. President Donald Trump has signed a decree renaming Lake Ontario as ‘American Lake,’ escalating tensions with Canada amid an ongoing trade dispute.

President Donald Trump announced on Thursday that he has officially renamed Lake Ontario, one of North America’s five Great Lakes, as ‘American Lake.’ The decision, made through an executive order, was described by the President as ‘immediately effective.’ The provocative move has intensified already strained relations with Canada, which shares the lake with the U.S. across its border with the province of Ontario.

The renaming follows a breakdown in trade negotiations between the U.S. and Canada, which led to heightened tariffs being imposed by both nations over the weekend. In a video message accompanying the announcement, Trump showed a map using the new designation and stated that the U.S. does not ‘anticipate doing much business with Ontario anymore.’ Critics have characterized the decree as a symbolic affront aimed at further pressuring Canada in the trade dispute.

This is not the first time Trump has sparked controversy during his second term with territorial or geographic claims. On his first day of this presidency, he issued an order renaming the Gulf of Mexico as the ‘Gulf of America,’ a change that Mexico has refused to acknowledge despite its appearance on official U.S. maps. The latest action has once again raised concerns among U.S. allies about the implications of Trump’s foreign policy, especially as it pertains to neighboring countries and regional cooperation.