Hillary Clinton, a likely U.S. presidential candidate, is urging the world to take action and address "the great unfinished business of the 21st century" -- the achievement of equality for women that 189 nations called for at a groundbreaking U.N. conference 20 years ago.

Clinton came to the Beijing conference as the U.S. first lady and brought delegates to their feet in a keynote speech that inspired women around the world when she declared: "Human rights are women's rights and women's rights are human rights." In the introduction to a new report on the status of women in 2015, she recalled those words and said the latest data provides evidence that advancing the full participation of women and girls expands global prosperity and stability.

The report entitled "No Ceilings," being released Monday, assesses the gains and gaps for women and girls since the 1995 conference and concludes that "there has never been a better time to be born female." But it says change has been far too slow when it comes to women's security, economic opportunity and leadership.

"I hope it serves as a wake-up call, and also as a call to action for us all," Clinton wrote. "Unlocking the potential of women and girls around the world is both the right thing to do and it is also the smart thing to do."

According to the acknowledgments, the report grew out of "the mutual commitment" of Melinda Gates and Hillary and Chelsea Clinton to women's and girls' rights and opportunities. The Bill and Melinda Gates Foundation and the Bill, Hillary and Chelsea Clinton Foundation joined forces with The Economist Intelligence Unit and the WORLD Policy Analysis Center at UCLA to produce it.

On the plus side, the report said more than 95 per cent of the 56 national constitutions adopted after 1995 guarantee gender equality, compared with 79 per cent of those enacted earlier. The life span of girls born today is almost 73 years, on average, about four years more than in 1995. The number of women who die in childbirth has decreased by 42 per cent globally since 1995, with the biggest reduction in South Asia. Girls and boys attend primary school at nearly equal rates worldwide -- and primary school is now tuition-free in almost 90 per cent of low-income countries.

"Today, women and girls have a much greater chance to live healthy and secure lives, and their fundamental human rights are now protected by law in many countries throughout the world." the report said. "Women and girls have access to educational and work opportunities that were previously unimaginable."

But on the negative side, the report said more than 170 countries currently have legal barriers in place that prevent women and girls from experiencing the same rights, protections and liberties as men and boys. An estimated 1.4 million girls are never born every year, largely due to the preference for sons in China and India. Violence against women remains "a global epidemic" with one in three women worldwide experiencing physical or sexual attacks. An estimated 200 million fewer women than men are on the Internet in the developing world, and 300 million fewer women own a mobile phone.

The report said even when there is progress, a woman's chance of equal rights and opportunities is often determined by geography, income, age, race, ethnicity, disability, sexual orientation and cultural norms.

"Only by getting data into the hands of citizens and leaders alike on what effective steps have been taken -- and what haven't -- can we close the gender gap in our global community," said Dr. Jody Heymann, founding director of the UCLA centre and dean of its School of Public Health.

She said in an interview that there has been progress on the legal and policy front in every region and in countries at all income levels. She also cited some important progress -- 50 countries expanded the length of paid maternity leave and 32 countries increased the age of marriage with parental consent.

But Heymann said "most importantly and strikingly is the extent to which unequal opportunities in 2015 still remain embedded in the law."

She said 61 countries allow girls to be legally married at a younger age than boys, and more than 150 countries lack protections critical to ensuring women's economic participation such as anti-discrimination laws, access to capital and leave for caregivers.

Melinda Gates said in the introduction that it's "frustrating" to see how many areas there are where data show progress is lacking.

"But when we identify the biggest gaps we have what amounts to a blueprint for action," she said.