Ontario Premier Doug Ford has responded to US President Donald Trump by installing a large sign on Canada’s shoreline declaring: “Lake Ontario. Now and Always.”

The move follows an executive order signed by Trump seeking to rename Lake Ontario as “Lake America”. The US president has also shared a series of AI-generated videos relating to the lake, which is shared by Canada and the United States.

Ford strongly rejected the proposed name change, saying the lake had been known as Lake Ontario long before Trump became president and would continue to carry the same name after his presidency.

The dispute comes amid growing tensions between Canada and the United States following the collapse of trade negotiations between the two countries.

The US has imposed new 50% tariffs on approximately $20bn worth of Canadian goods, escalating the ongoing trade dispute.

Canada has announced plans to respond with equivalent measures, with “dollar for dollar” counter-tariffs expected to take effect next month.

The Lake Ontario sign has become the latest symbolic exchange between Canadian and US political leaders as disagreements over trade and the lake’s name add to tensions between the neighbouring countries.