Years before becoming Canada's Prime Minister, Justin Trudeau recruited women into politics so he could stack his cabinet with them once elected

When then-newly-inaugurated Canadian Prime Minister Justin Trudeau was asked almost two years ago why having a gender-balanced cabinet was so important to him, he shrugged and said, "Because it's 2015."

At the time, he was introducing a cabinet he said "looks like Canada" that was split evenly between 15 men and 15 women.

But years before becoming Prime Minister and creating his ideal cabinet, Trudeau had to set a plan into action to get to this point.

"Before it could be 2015, it had to be 2014, 2013, 2012," Trudeau said Tuesday at Fortune's Most Powerful Women Summit.

During his talk, the PM detailed how, for years before getting elected, he actively recruited women into politics so that, down the road, he could recruit them to his cabinet.

Trudeau said his team sent mailers to his party's mailing list as part of his "Ask Her To Run" campaign that asked questions like, "Do you know a woman who is strong and civically-minded and would be a great addition to politics?" and that suggested members encourage these women to run.

"Studies have shown that, when you ask a woman to run for politics, her first question to you is, 'Really? Do you think I should do it?' or 'Why me? Do you think I would be good at it?'" Trudeau said. "Whereas, if you ask a man, his question is usually first, 'What took you so long to ask me?'"

"You have to work and encourage and drone" to get more women into politics, Trudeau said.

The PM cited the example of one of his cabinet members, Chrystia Freeland, who was working for Reuters as an economic journalist in New York with a young family when he asked her to run for parliament.

"I asked her to run for politics, which involved leaving New York to move to Toronto to run for a nomination that I couldn't guarantee she was going to win and then run in a by-election as a distant third party candidate so that maybe she could move to Ottawa. And when I first asked her, she hesitated," Trudeau said. "And it took weeks of asking her and appealing to both service but also … saying, 'we need your voice.'"

In the end, Trudeau said all that hard work and cajoling paid off.

Having a gender-balanced cabinet "was really important, and it has led to a better level of decision-making than we could have ever imagined," Trudeau said. "It wasn't just the right thing to do - it was the smart thing to do."