(VOVworld)- Heads of state and government gathered on Monday at the third international U.N. financing for development conference in the Ethiopian capital, Addis Ababa.

During the 5-day event, they will discuss fundamental ground rules for a fairer world of inclusive, low-carbon growth. In concrete term, that means deciding how to fill a colossal annual investment gap in key sustainable development sectors for developing nations -- estimated at up to $2.5 trillion annually according to the UN's trade and development body UNCTAD. This in turn will enable the world body to push ahead with its 2015-2030 Sustainable Development Goals, which are due to be formally adopted in New York in October. There are 17 in all, ranging from ending poverty to providing universal access to sustainable energy.