Ontario Premier Doug Ford responded to President Donald Trump's "Lake America" decree on Saturday with a billboard-sized message erected on the Canadian shoreline: "Lake Ontario. Now and Always."

Wearing a Team Canada soccer jersey, Ford unveiled the sign near Grimsby, Ontario, and posed for photographs. The 24-by-12-foot (7.3-by-3.6 meter) sign stands on 6-foot (1.8-meter) legs, placing its top roughly 18 feet (5.5 meters) above the ground — about two stories high. The message is also repeated in French.

The gesture was the latest act of defiance after Trump signed an executive order directing U.S. federal agencies to call Lake Ontario "Lake America." Following months of tariffs, threats to make Canada the 51st U.S. state, and personal attacks on its leaders, the move has been met in Canada largely with ridicule.

Ford said Trump was attempting to rename the lake because Ontario and Canada were "standing up for ourselves," and argued the name would outlast the president.

"Long after President Trump is gone, it will still be called Lake Ontario," Ford said in a video posted on social media.

Manitoba Premier Wab Kinew compared Trump to an aging rock band trying to revive an old hit.

"You know when a rock band is really over the hill and you see them like in a casino playing some song from like 50 years ago. I think that's the part of Donald Trump's presidency we're at now. Like he thought they had a real hit, a real golden oldie, with the Gulf of Mexico," Kinew said, referring to Trump's executive order renaming the Gulf of Mexico the Gulf of America. "And he's trying to bring back that, and he's trying to play the hits for his base. But I think everybody here thinks it's a little sad and it's not his best work."

The mockery was not limited to politicians. Canadian historian Robert Bothwell was even more scathing.

"The greatest country on earth takes this moron seriously?" Bothwell said.

But Bothwell said the dispute was more serious than the jokes suggest, arguing that Trump's broader aim was "to subordinate Canada and at best make it a colony, at worst absorb it into the United States."

Nelson Wiseman, professor emeritus at the University of Toronto, said Trump "would like Canada to act like a vassal state, but it refuses to do so. That irritates him."

The dispute comes as relations between the longtime allies deteriorate over trade. Negotiations collapsed last week, both governments accused the other of making late demands, and Canada announced retaliatory tariffs set to take effect next month.

Trump's order also arrived amid an escalating war of words with Ford. In an interview with The Associated Press earlier this week, Ford said Ronald Reagan would be "throwing up" over Trump's tariff policies and "disgusted with President Trump."

Trump fired back by dismissing Ford's comments as "bluster," calling him Prime Minister Mark Carney's "flunky" and mocking him as the "less charismatic, intelligent, and overall unimpressive brother" of the late Toronto Mayor Rob Ford.

Trump continued promoting the new name on Saturday, reposting a meme showing Canada geese with Trump-like blond hair firing rifles as they "protected" Lake America.

Trump has repeatedly used maps to make political points. A "Gulf of America" map was displayed for a time beside the Resolute Desk in the Oval Office, and Trump has posted images depicting Canada as part of the United States or as the 51st state.

As with the Gulf of America renaming, the practical reach of Trump's order is limited to U.S. federal usage: such directives change how American government agencies refer to geographic features, but they carry no legal force in other countries, and international bodies and foreign governments are under no obligation to follow them. Similar past presidential renamings have largely failed to displace names in common international use.

The name Lake Ontario derives from the Huron Indigenous people's word "oniatarí:io," which means "lake of shining waters." The Canadian province of Ontario, founded in 1867, took its name from the lake. Lake Ontario is one of the five Great Lakes shared by Canada and the United States, making any unilateral renaming on the American side of the border largely symbolic for the Canadians who live along its northern shore.

Canadian Prime Minister Mark Carney rejected the move, noting the lake's Indigenous roots and that its name predates both Canadian Confederation and the U.S. Declaration of Independence. Trump cannot require Canada to adopt the new name.

This story was originally featured on Fortune.com.