MONTEBELLO, Que. -- Tom Mulcair may be 17 years older than Justin Trudeau, but he's not about to let his age keep him from leading the New Democrats into the 2019 election.

The NDP leader, who continues to be grilled about his own political fate in the wake of October's election defeat, will be days shy of his 65th birthday the next time Canadians head to the polls.

That's not holding him back.

"Are you saying that my friend Bernie Sanders is too old to be running for the White House?" Mulcair said in an interview with The Canadian Press on the sidelines of his party's caucus retreat in Montebello, Que.

"I think that passion keeps us young and I'm very passionate about what I do and what the NDP can accomplish."

Mulcair wants to continue to lead the party, which now has 44 seats in the House of Commons. To do so, he'll need to see a strong show of support from delegates at the upcoming NDP convention in April.

Later this week, Mulcair is scheduled to meet with members of the NDP executive as the party continues to sift through the wreckage of the October election, which reduced it from front-runner to third-party status.

Mulcair said he also held his own meetings immediately after the campaign with organizers, community groups and others who played a role in the race.

"It was an extraordinary experience," he said.

"For me, it was just sitting there and listening, reacting a little bit, but mostly just listening, taking notes to what people had experienced on the ground. What had gone right with the campaign, what had gone wrong. What lessons we had to learn going forward."

In his discussions, Mulcair said he also learned there is an "incredible resource" in the ridings of supporters who are often in their mid-30s and have been connected to the NDP since they were teens.

"They wear the NDP's values of fairness and solidarity and justice in everything they do in their lives ... that's what has brought to them to the party," he said.

"What we are doing now is connecting with that base."

It is important to ensure that support at the riding level is also connected to the party apparatus and the NDP's parliamentary wing, Mulcair added.

"That all has to be one from now on, and it wasn't," he said. "I take responsibility for the fact that that came up short, but that's a top priority for me ... to work on that and to get that mix right."

New Democrats also need to spend more time talking about what they stand for, such as tackling inequality in Canadian society, Mulcair added.

"We believe in a positive, proactive role of government in reducing inequality."

Mulcair and his team plan to press the Liberal government to pursue a progressive agenda in Parliament when they return to Ottawa next week.

NDP MPs spent two days in strategy sessions while the party tried to carve out its road map to rebuild and move forward.

"This, I would say, was probably one of the best caucus meetings I've attended since I was first elected in 2004," said NDP caucus president Charlie Angus.

"We were focused, we were energized ... it was a very, very good, very frank and very functional meeting in terms of getting down to how we are going to start laying out our strategy in the House of Commons."