Prime Minister Justin Trudeau waves a flag as he takes part in the annual Pride Parade in Toronto on Sunday, July 3, 2016. [Photo/IC]

TORONTO - Canada's largest Pride parade in Toronto marked another milestone Sunday as a sitting prime minister marched for the first time in a colorful celebration that also paid tribute to Orlando victims in last month's shooting massacre in the United States.

"We have to speak up anytime there is intolerance or discrimination," said Justin Trudeau as the 36th annual parade kicked off in downtown Toronto.

Members of the crowd, some decked out in rainbow gear and outlandish costumes, posed for selfies with the prime minister while others chanted his name as he passed by.

But Trudeau downplayed his appearance at the parade as no big deal, noting he'd been attending Pride parades for years. "It shouldn't be a big thing that the prime minister is walking in the Pride Parade and from now on, it won't."

Prominent in the procession was a pair of marchers who held a large black banner that read "Orlando" and "We march for those who can't."

The prime minister said the Orlando tragedy was a reminder that "we can't let hate go by."

Trudeau, Ontario Premier Kathleen Wynne and Toronto Mayor John Tory were all marching in this year's parade, marking the first time leaders from all three levels of government have participated in the event together.

When asked about how far Canadians have come to advance LGBT (lesbian, gay, bisexual, and transgender) rights, Trudeau said there has been a lot of progress.

"We owe a tremendous amount to everyone who has been fighting to get to the day we are today but we have a lot more work to do," he said.

The parade attracted tens of thousands of people to the downtown core and wrapped up a month-long Pride festivities in Toronto.

The Orlando shooting resulted in tighter security at the parade. Police officers, many wearing uniforms with the Pride rainbow on them, were visible even along streets adjacent to the parade route.

The parade briefly stalled when activists from the Black Lives Matter movement staged a sit-in on the parade route. The sit-in ended peacefully and the parade continued.