UN Secretary General Ban Ki-moon pledged to strike a gender balance in the UN senior management as the world body prepares to mark International Women's Day this week.

Women continue to be under represented in the decision-making machinery of world governments, Ban told the UN General Assembly Tuesday.

'I pledge to work for a collaborative and coordinated approach to gender perspectives - one that involves and engages the entire UN system in supporting member states' work for gender equality and empowerment of women,' he said.

Ban named Tanzania's former foreign minister Asha-Rose Migiro as his deputy, the second highest-ranking post in the UN. He also named Alicia Barcena of Mexico as undersecretary general for management.

Previous secretaries general had pledged to give women 30 percent of the top UN posts but none fulfilled the promise.

International Women's Day is being observed Thursday allowing the UN to highlight weaknesses in programmes to uphold women's rights.

The UN said women's work continues to be undervalued and under-represented in decision-making positions. Of the estimated 100 million children not in school worldwide, the majority are girls. The majority of illiterate adults are also women.

'Worst of all, violence against women and girls continues unabated in every continent, country and culture,' Ban said. He called on men to meet their responsibility to end the violence against women and girls.