(UNITED NATIONS) — U.N. Secretary-General Antonio Guterres warned Thursday that inequality for women is growing and it “should shame us all in the 21st century because it is not only unacceptable, it is stupid.” The U.N. chief said in a speech at the New School in New York that gender inequality and discrimination against women is the “one overwhelming injustice across the globe — an abuse that is crying out for attention.” “Everywhere, women are worse off than men, simply because they are women,” he said, and minority, migrant, refugee and disabled women “face even greater barriers.” Guterres said gender inequality is “a stain,” just like slavery and colonialism were in previous centuries. He said young women like Malala Yousafzai, the Pakistani schoolgirl who campaigned for girls’ right to education after surviving being shot by Taliban militants, and Nadia Murad, the Nobel peace laureate who survived enslavement and sexual abuse by Islamic State extremists in Iraq, “are breaking barriers and creating new models of leadership.” But despite these advances, Guterres said, “the state of women’s rights remains dire.” “Progress has slowed to a standstill — and in some cases, been reversed,” he said.