World leaders are due to adopt a set of development objectives - known as the Sustainable Development Goals - in September that include ending poverty, reducing child mortality and tackling climate change, to replace the eight expiring U.N. Millennium Development Goals (MDGs).
Some 2.6 billion people have gained access to clean water and 2.1 billion gained access to toilets since 1990, but large gaps remain, especially in sub-Saharan Africa, according to the report.