WASHINGTON -- Sophie Gregoire Trudeau kicked off a United Nations-led girls' conference in Washington with a pep talk Monday, urging young women to believe in themselves and in their ability to shape the world.

The prime minister's wife referred to her own past eating disorder and talked about the ways young girls often lack confidence, in their appearance or in their ability.

She opened the Girl Up Leadership Summit urging the hundreds of young women in attendance to fight back against that lack of confidence.

She also promoted Canadian international development programs, tailored to helping women.

Gregoire Trudeau said it's a basic economic truism that societies with empowered women are more prosperous.

"When women rise, men rise as well... It's based on facts," she said. "We have more women in the boardroom, more women in classrooms, more women in community life, we can inject peace.

"We can inject compassion."

She delivered a string of extemporaneous remarks, wandering around the stage as she spoke off-the-cuff, and got an ovation from the crowd at the beginning and end.

She concluded by paraphrasing the South Asian-Canadian poet Rupi Kaur, who wrote about her heart aching for sisters more than anything.

"My heart aches for women helping women; like flowers ache for spring," Gregoire Trudeau said.

"You are loved, girls... I wish you could see just how beautiful you are and how possible it is to self-love, and be at peace."