Fans at the FIFA World Cup opening ceremony in Toronto, Canada, could be heard booing as the United States' flag was presented Friday afternoon.

The change in mood was noticeable after cheers were heard for the Canadian flag during the ceremony, and came after some boos could be heard by those in the stadium in Mexico during Thursday's opening ceremony.

Canadians were also heard booing the U.S. Thursday, during the FIFA Fan Festival in Toronto, where spectators watching the live broadcast from Mexico also broke into boos when the U.S. was introduced as one of the three host nations.

The competition is set to take place across the three countries over the next few weeks, with the U.S. having drawn criticism for its approach to immigration, as well as its ongoing conflict with Iran in the Middle East.

This is a breaking news story. Updates to follow.