U.N. Secretary-General Ban Ki-moon will announce on Wednesday a $40 billion launch to a plan to save the lives of 16 million women and children over the next five years, U.N. officials said.

The drive aims to make headway on the slowest-moving sectors of the Millennium Development Goals (MDGs) set by the world body 10 years ago -- maternal and child health.

It was announced on the final day of a U.N. summit designed to speed progress on all eight goals, which also seek to slash poverty and combat disease.

It's the first time we've seen across-the-board agreement on how we approach women's and children's health, Robert Orr, a senior aide to Ban, told Reuters, adding that the plan would be endorsed by the 192 U.N. member states.

A U.N. statement said more than $40 billion had been pledged by governments, foundations, businesses and non-governmental organizations.

Of that, U.N. officials said, nearly $27 billion was new money being announced by governments -- indicating the rest had already been committed since plans for a global strategy for women's and children's health were first disclosed in April.

Nearly or $8.6 billion was coming from low-income countries, they said.

The U.N. argues that investing in the health of women and children reduces poverty and stimulates economic growth.

The statement listed 40 developed and developing countries that were implementing new health policies and increasing funding. It was unclear how much of the pledged money was to be spent domestically and how much donated in overseas aid.

In addition to saving lives, the global strategy would seek to prevent some 33 million unwanted pregnancies by 2015, the year in which the MDGs are set to be completed, it said.

Orr said that if 16 million lives were to be saved, the total sum needed would be as high as $169 billion. He said the $40 billion launch was expected to attract further pledges in coming years.

The statement described the global strategy as a roadmap that identifies the finance and policy changes needed as well as critical interventions that can and do improve health and save lives.

Four U.N. agencies and the World Bank would join forces to mobilize support for the strategy, it said.