Defence Minister Harjit Sajjan formally apologized Thursday to the survivors of a deadly cadet camp explosion more than 42 years ago, as he announced the terms of a settlement between them and the federal government.

But Sajjan stopped short when asked whether the government will increase the levels of support and compensation for cadets who suffer long-term injuries or illness in uniform today.

That is despite concerns raised by some survivors and the Canadian Forces ombudsman, who says little has changed in terms of helping ill and injured cadets since 1974.

"The programs that are in place for the leadership, for the training, and also to look after them, have evolved in many ways," Sajjan said in announcing the settlement.

"I'm very proud of the program and how we look after our cadets."

Sajjan was flanked by some of the former cadets and first responders who were at the camp in Valcartier, Que., on July 30, 1974, when a grenade exploded in a crowded barracks.

The accident, blamed on a live grenade being mixed with several dummies, killed six teens between the ages of 13 and 15 and left dozens more with lifelong physical and psychological injuries.

One of the survivors was Michel Juneau-Katsuya, then 14, who later served with the RCMP and Canadian Security Intelligence Service before leading settlement negotiations with the government.

Juneau-Katsuya told The Canadian Press each of the survivors dealt with the explosion differently, with some having successful careers while others suffered from PTSD or committed suicide.

"My coping mechanism until recently was to push it as far and as deep as possible," he said. "I was able to have a successful career in the RCMP and CSIS, but the box was there and was leaking constantly."

An official board of inquiry was held after the explosion, but it wasn't until military ombudsman Gary Walbourne issued a scathing report in 2015 that the government agreed to address the long-term effects.

Walbourne, whose investigation was prompted by complaints from several survivors about the military's handling of the incident, found the boys had been treated unfairly.

In particular, he found they had received much lower levels of physical, mental and financial assistance than their instructors and other military personnel involved.

Thursday's settlement was the result of nearly two years of negotiations and included an apology from Sajjan for the length of time it took for the government to help those affected.

"To the more than 100 survivors of this incident, to their families and to the families of those of the deceased, on behalf of the government of Canada, I ask you to accept this apology," Sajjan said.

"We're truly sorry for the pain you have endured and we deeply regret how long it took to address it. Today we begin to correct the mistakes of the past."

The families of the six boys killed in the explosion will receive a one-time payment of $100,000 while survivors or their families, if they have since died, will be eligible for a one-time payment of $42,000.

Survivors can also apply for additional compensation worth up to $310,000 for pain and suffering while National Defence will also cover any related health-care costs not already covered by their province.

National Defence estimates up to 155 former cadets and first responders or their families will be eligible, though exact numbers aren't known.

Walbourne wrote on Twitter that he was pleased there had "finally been a resolution" to the Valcartier tragedy.

"However, there remains a significant insurance gap for cadets," he wrote, before referencing a report he released in January that found little had changed for ill and injured cadets since 1974.

The maximum a cadet can receive for a lifelong injury or disability is $20,000, the report said, unless the cadet or their family fight for more compensation in court.

That compared to $100,000 for civilian volunteers and $250,000 for military personnel and reservists, plus workers' compensation and benefits from Veterans Affairs Canada.

While happy to finally have some closure, Juneau-Katsuya said he and others will keep working to make sure all cadets are treated fairly and no one else has to go through what they did.

"Our work is not done yet," he said. "We're still going to be working and make sure we will become advocates for future cadets."

About 54,000 young people between the ages of 12 and 18 are enrolled in the land, sea and air cadets. The program has a budget of about $250 million and relies on serving personnel, reservists and instructors drawn from local communities who receive commissions as military officers.