Lieutenant-General Frances Allen has been named vice chief of the defense staff, the military said in a statement.

"I am very pleased to see a strong woman in the vice chief position for the first time in Canada's history," Trudeau told a news conference.

Her nomination follows accusations reported in the Canadian media and now being probed by military police of inappropriate behavior and relations with subordinates against former top soldier General Jonathan Vance -- which he has denied. Vance retired in January before these were made public.

Weeks later, his successor Admiral Art McDonald also stepped aside after an investigation was launched into separate allegations against him.

Trudeau said the senior leadership must "move forward on ending the challenges of harassment and discrimination in the military... and ensuring that anyone who comes forward to share stories or allegations is given the support and resources that they need."

He acknowledged that measures taken to date to address these issues "didn't go far enough, and they haven't moved fast enough."

"It's my commitment that we will be moving faster and going further to make sure that anyone who serves their country... has a safe workplace," he said.

The Canadian military has long struggled with allegations of sexual misconduct, with the number of complaints rising in recent years and now suddenly reaching the top brass.

In 2019, a federal court awarded 700 military victims of sexual harassment, sexual assault and gender-based discrimination almost Can$1 billion to settle a class action.

This followed a 2015 report by a retired Supreme Court justice that found the military had "an environment that is hostile to women... and is conducive to more serious incidents of sexual harassment and assault."

Vance had launched a review to ensure the proper handling of complaints. When he was sworn in, McDonald also spoke about the need for a culture change in the military.

Trudeau's defense minister, Harjit Sajjan, is now under fire for not taking swifter and firmer action against Vance, who was appointed by the previous Tory administration.

Replacing McDonald, Lieutenant-General Wayne Eyre has been made acting chief of the defence staff.

Allen, who has had a long military career -- including representing Canada at the NATO military council and heading the army's cyberspace division -- will be responsible for the military's day to day operations and report directly to Eyre.

She replaces Lieutenant General Mike Rouleau who after just one year in the job takes on a new role as advisor to Eyre on modernizing the military and procurement.