Berlin (dpa) - UN Secretary General Antonio Guterres made a heartfelt plea for gender parity in an editorial in the Sunday edition of Germany's Frankfurter Allgemeine Zeitung, coinciding with International Women's Day.

"The 21st century has to be the century of equality for women," Guterres wrote. "It is time to stop trying to change women, and time to start changing the systems that prevent them from fulfilling their potential."

Guterres criticized that for every three lawmakers who are men in parliaments around the world, there is only one woman.

And he commented that far more men than women work in the tech sector, in universities and in start-ups.

Guterres called gender inequality the "main injustice of our times and the greatest challenge for human rights."

Women are confronted daily with men's sexism and know-it-all attitudes, and are blamed for this, even as they are victims, Guterres wrote.

In a report published on Friday ahead of International Women's Day, Guterres wrote that women have made significant progress in terms of raising the number of girls who can attend school and abolishing discriminatory laws.

But he noted that, "some countries have rolled back laws that protect women from violence." And he criticized that women's sexual and reproductive rights are still threatened.