Montreal Mayor Valérie Plante and St. Catharine's, Ont., Mayor Mat Siscoe have been excluded from an annual meeting with White House officials scheduled for Friday.

The meeting, organized by the Great Lakes and St. Lawrence Cities Initiative, a bilateral coalition of over 244 municipal and regional mayors, will proceed as planned as part of the annual Great Lakes Day event in Washington, but exclusively with American mayors.

Christine Maydossian, a spokesperson for the coalition, told CBC News that the White House had been aware of the meeting for the past month, but on Wednesday, it said Canadian mayors would not be welcome.

"The Cities Initiative was informed on Wednesday, March 5th, 2025, for the first time, and just 48 hours before the planned meeting, that due to diplomatic protocol, there wasn't enough time to process the requests of the Canadian mayors," she said.

According to her, as a result, Plante and Siscoe were replaced by U.S. mayors at the meeting. 

Laval, Que., Mayor Stéphane Boyer said he wasn't surprised by the decision given the current political context. 

"They say it's for security reasons, that they haven't had time to check people's identities," he told Radio-Canada. "I think it's a political move to refuse representatives of Canada."

Still, Boyer believes the decision is unlikely to have a major impact. 

"I believe that the first people who can put pressure on the Americans are American companies, American citizens, American elected officials, and that's what we have the opportunity to do, to meet several of them to try to get them to carry our message."

The mayors of Montreal, Laval and Quebec City Mayor Bruno Marchand travelled to the U.S. capital this week. They will continue to meet with other American elected officials — both Democrats and Republicans.

On Radio-Canada's Tout un matin Thursday morning, Plante said the mayors are taking the opportunity to plead their case against President Donald Trump's 25 per cent tariffs and raise awareness about the consequences of this controversial move.