MISSISSAUGA, Ont. -- Conservative Leader Erin O'Toole says hoisting the Canadian flag back up on Parliament Hill on the first national day marking the legacy of residential schools should be seen as a sign of commitment to build a better country.

At a Friday campaign event in Mississauga, Ont., O'Toole doubled down on his pledge from Thursday night's English-language debate to return federal flags to full-mast on Sept. 30, the National Day for Truth and Reconciliation.

They have flown at half-mast at the Peace Tower and other federal buildings since May 30 after the discovery of hundreds of unmarked graves on the grounds of former residential schools.

O'Toole said Orange Shirt Day, which honours children forced into the residential school system, is an opportunity to recommit to reconciliation and partner with Indigenous communities to make "real progress."

"I'm very proud of our country, despite the scars of our past," he said, speaking outside a legion hall along the Credit River, an erstwhile fishing and trading route for the ancestors of the Mississaugas of the New Credit First Nation.

"We will then raise our flag as a sign of that commitment of building a strong and better Canada in the future."

Throughout the election campaign, O'Toole has stressed pride in Canadian heritage, a theme he drives at his rallies in tandem with military appreciation.

"If you don't love and recommit to your country, are you really going to dig deep to make progress?" he asked.

O'Toole added that he has consulted with Indigenous leaders "literally every week or so" during his more than 12 months as Conservative leader, but did not specify whether any of the conversations concerned flags.

Manitoba's NDP Opposition Leader Wab Kinew, who was an honorary witness to the Truth and Reconciliation Commission of Canada, which heard testimonies from residential school survivors, tweeted Thursday the Canadian flag should fly at half-mast Sept. 30.

"The day is about the Survivors and their descendants. … And those who never came home," he wrote.

Parliament hurried passage of the bill that created the statutory holiday in June after the discovery of what was believed to be the graves of 215 Indigenous children who attended a former residential school in Kamloops, B.C.

At the time, Canadian Heritage Minister Steven Guilbeault said the point of the national holiday was to create a chance for Canadians to learn about what happened in the residential school system and reflect on the experiences of survivors.

Liberal Leader Justin Trudeau rejected the notion that residential schools are relegated to the history books.

"I think Canadians have seen with horror those unmarked graves across the country and realized that what happened decades ago isn't part of our history, it is an irrefutable part of our present," he said Friday.

"I plan to keep those flags at half mast until it is clear that Indigenous Peoples are happy to raise them again.

"Unlike Mr. O'Toole, who will do it when he feels like it, I will continue to put reconciliation with Indigenous peoples in the hands of Indigenous Peoples."

Less than an hour later, O'Toole said Trudeau has offered only "positive words and promises," pointing to the dozens of Indigenous communities that lack access to clean drinking water.

Trudeau promised in 2015 to lift all drinking water advisories by this March, but the government acknowledged last December it would not meet that goal.

As of Aug. 28, 109 long-term drinking water advisories have been lifted since November 2015, while 51 remain in effect across 32 communities, Indigenous Services Canada said.

New Democrat Leader Jagmeet Singh has said symbolic measures such as lowering flags are important, but must not supersede other priorities, including improving living conditions for Indigenous communities and locating more unmarked gravesites.

This report by The Canadian Press was first published Sept. 10, 2021.