"The status of the world’s women is not only a matter of justice. It is also a political, economic, and social imperative," she added to loud applause from dozens of government ministers and more than 2,000 women activists attending the meeting.
The 12-day conference was held to review progress since the adoption of the declaration at the 1995 world conference on women in Beijing.
That declaration is the most comprehensive global policy framework to advance the goal of women's empowerment and gender equality around the world.
Clinton noted that 15 years after the Beijing declaration, it was time to declare "with one voice that women’s progress is human progress and human progress is women’s progress, once and for all."
She said that principle was also at the heart of US foreign policy.
"We believe that women are critical to solving virtually every challenge we face as individual nations and as a community of nations," Clinton noted. "The world cannot make lasting progress if women and girls are denied their rights and left behind."
And she said Washington was implementing this approach in its strategy in Afghanistan, stressing the need to involve Afghan women "at every step of securing and rebuilding their country."
The conference ended with the adoption of seven resolutions aimed at improving the economic status of women around the world, combating genital mutilation of women and girls and ending maternal mortality.
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