The three prime contenders in the federal election all expressed concern about youth vaping while on the campaign trail Thursday, but they stopped short of committing to measures that would see Canada impose a ban on vaping-related products.

Vaping is believed to be linked to hundreds of serious lung illnesses and at least six deaths south of the border, and the U.S. government said earlier this week it would ban most flavoured products, especially those appealing to children.

The Conservative, Liberal and NDP party leaders all declined direct comment on the U.S. government move.

"We are always looking to do more to keep Canadians safe, but our decisions will be made based on evidence, based on data," Liberal Leader Justin Trudeau said at a campaign stop in Victoria. "We will have more to say as Health Canada continues to do its work keeping Canadians safe including from the dangers of vaping."

NDP Leader Jagmeet Singh expressed concern about the impact of vaping on Canadian youth, but did not outline specific measures to tackle the issue.

"I want us to make good decisions and good policies that protect the safety and health of Canadians and everything we do should be with that focus in mind," Singh said in Brampton, Ont. "If there is a way to move forward that discourages young people from making a bad decision, I want to do that."

Conservative party Leader Andrew Scheer, meanwhile, said any decisions he would make would be informed by the outcome of the recent measures unveiled in the U.S.

In announcing the flavour ban on Wednesday, a White House spokesman said the Food and Drug Administration will develop guidelines to remove all e-cigarette flavours except tobacco from the market.

"I haven't seen specifically the new regulations that the U.S. government has put in, but we'll certainly take a look at that," Scheer said during an announcement in Toronto, adding his party would support measures that would discourage children and teens from taking up "tobacco habits."

Health Canada said in a statement that there are already measures in place meant to discourage youth vaping.

The 2018 Tobacco and Vaping Products Act prohibits the sale and restricts the promotion of vaping products to a person under 18, specifically those with candy or dessert flavours.

"Health Canada is concerned about the uptake in youth vaping and has been pursuing a comprehensive suite of actions to address youth vaping," Health Canada said, citing a national public education campaign on the risks associated with the practice and ongoing research on its health effects.

The statement also said Health Canada has conducted multiple consultations on further restricting vaping product advertising.

A spokeswoman said the agency has not received reports of any pulmonary illnesses related to vaping, but has nonetheless issued a warning urging those who vape to watch for symptoms such as a cough, shortness of breath and chest pain.

The Public Health Agency of Canada has also asked provincial officials to report any possible incidents of pulmonary illness associated with vaping.