Michelle Obama says that while women are breaking barriers and excelling in careers their mothers and grandmothers believed were off-limits, more progress is needed to achieve true equality.
American women still earn less than men and lag in math and science fields, she said Tuesday, while many foreign countries exclude female voices from government decision-making.
Still, the first lady said: "We've come a long way, ladies."
"We as a nation benefit from every girl whose potential is fulfilled, from every woman whose talent is tapped. We benefit as a nation," Mrs. Obama said at a White House reception celebrating women. "We as a nation benefit from their intelligence, from their hard work, from their creativity, from their leadership.
"And that's not just true here in America," she said. "Time and again, we have seen that countries across the globe are more prosperous, they're more peaceful when women are more equal and have the rights and opportunities they deserve."
Mrs. Obama echoed comments earlier in the day by Secretary of State Hillary Rodham Clinton, who implored the Middle Eastern countries of Egypt and Tunisia, which are undergoing a transition from autocracy to democracy, to let women make decisions, too.
"The United States will stand firmly for the proposition that women must be included in whatever process goes forward," said Clinton, who was joined at the event by Mrs. Obama. "No government can succeed if it excludes half of its people from important decisions."
At the White House, Mrs. Obama told her mostly female audience that their presence was a "perfect illustration" of the progress made since International Women's Day was first celebrated 100 years ago.
She said American women are now the majority of college graduates and nearly half the work force. They're leaders in business and serve at the highest levels of government and the military, she said.
"While we've made some important strides, all of you in this room know better than anyone else that this work is far from finished," she said. "We have so, so much more to do."
The events at State and the White House commemorated International Women's Day. The White House event also recognized March as Women's History Month in the U.S.
At the State Department, Clinton also recognized 10 women for efforts ranging from promoting good governance in Cameroon to combating such scourges as sexual harassment in China, domestic abuse in Afghanistan and "honor killings" in Jordan.
Associated Press writer Bradley Klapper contributed to this report.