Streep on Thursday also called the allegations against producer Harvey Weinstein "the most gargantuan example of disrespect" permeating every industry.
She said women still don't have enough representation in leadership positions and that impacts how decisions are made. Streep said women in the entertainment industry are prepared to demand for equal representation in board rooms and other improvements to the American workplace.
"We are after 50/50 by 2020," she said to loud applause. "Equal means equal. And if it starts at the top, none of these shenanigans would have filtered down and it wouldn't have been tolerated."
Streep made the comments in a conversation with feminist icon Gloria Steinem at the Massachusetts Women's Conference in Boston.
"It's such an interesting moment, because this conversation about why this is so widespread, this is really worth having and it's fantastic," she said. "I can't help thinking it's just a door that's opening to a better world."
The 13th annual conference, which organizers say was attended by a record 16,000 people, also featured speeches from Academy Award-winning actor Viola Davis and fashion designer Diane von Furstenberg.
At the two-day conference's opening night Wednesday, Steinem took a shot at President Donald Trump, calling the billionaire the "harasser in chief."
More than a dozen women have said Trump sexually assaulted or harassed them over the years. He has denied the allegations.
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