UNITED NATIONS (AP)-- Secretary-General Antonio Guterres on Thursday decried the failure to bring women into peacemaking, pointing to statistics showing that between 1990 and 2017, women constituted only 8 percent of negotiators and 5 percent of witnesses and signatories to major peace processes.

He told the UN Security Council on Thursday that at the heart of these statistics -- which also include only 2 percent of mediators in conflicts being female -- is the continuing inequality between men and women.

Guterres said a recent study by the U.N and World Bank provides convincing evidence linking gender equality and peace -- and he urged all countries to invest in promoting the equality and empowerment of women, which he stressed is also critical to preventing and ending conflicts and building "peace and prosperity in the world for all." 

Phumzile Mlambo Ngcuka, who heads the UN agency promoting equality for women, said: "Women cannot be excluded from the peace process simply because they do not go into battle."

According to a 2015 study of 156 peace agreements by the International Peace Institute, a New York think tank, "when women are included in peace processes, there is a 20 per cent increase in the probability of an agreement lasting at least two years, and a 35 per cent increase in the probability of an agreement lasting at least 15 years."

But Mlambo Ngcuka said the indicators of women's involvement in peacemaking had all "stagnated or dropped" this year.

"Our continued tolerance for the limited recognition of women's expertise and lived experience is shameful," the executive director of UN Women said.

Mlambo Ngcuka said only three of 11 peace agreements signed in 2017 had provisions on gender equality, "continuing last year's worrisome downward trend." And only 25 percent of the 1,500 agreements signed between 2000 and 2016 included the role of women in implementing peace accords, she said.

Looking at current hotspots, Mlambo Ngcuka said efforts to resume a dialogue in war-battered Yemen don't include women, except in advisory bodies.

In Mali, women average "a dismal 3 percent" on the multiple national committees set up to monitor and implement a 2015 peace agreement, she said.

In Central African Republic, "mediation efforts are focused on the presidency and the 14 armed groups, and exclude women altogether," Mlambo Ngcuka said, and in Afghanistan, "when it comes to actual talks with the Taliban, women's absence is noticeable."

The council was meeting to discuss implementation of a landmark UN resolution on women, peace and security adopted in 2000 that calls for women to be included in decision-making positions at every level of peacemaking and peace building.

Guterres noted that almost 90 countries signed up to speak on Thursday, "but there is a significant gap between what we say in this chamber, and what we do outside."

"Every year, we make laudable commitments _ but they are not backed with the requisite financial and political support," he said. "We extol the positive influence of women peacebuilders, but provide little space for their participation. We rely heavily on women's organizations, but do not fund them adequately."

Guterres said he has formed a group to take emergency measures to increase the number of women in UN peace operations, stressing that it is "crippling" to the UN's credibility that women represent only 4 percent of its military peacekeepers and 10 percent of its international police.