India has made "moderate" progress in reducing open defecation rates among its population and has succeeded in providing access to improved drinking water to more people in urban and rural areas, according to a UN report.

The Joint Monitoring Programme report titled "Progress on Sanitation and Drinking Water: 2015 Update and MDG Assessment" released by the UN Children's Fund and the World Health Organization said one in every three or 2.4 billion people on the planet are still without sanitation facilities, including 946 million people who defecate in the open.

It said India is among the 16 countries that have reduced open defecation rates by at least 25 percentage points.

In India's case, there has been a reduction by 31 per cent in open defecation, a progress termed as "moderate" by the report.

"The Southern Asia region, where the number of open defecators is highest, has also made significant improvements. Bangladesh, Nepal and Pakistan have all achieved reductions of more than 30 percentage points since 1990," the report said.

"The 31 per cent reduction in open defecation in India alone represents 394 million people and significantly influences regional and global estimates," it said.

The report, however, noted that in India, there has been very little change over the last 20 years in reducing open defecation among the poor.

The report further said that India has "met its target" of increasing use of drinking water resources to its population.

India was among the nine countries that succeeded in halving the proportion of the population without improved drinking water in both rural and urban areas.

The other countries are Belize, Egypt, Jordan, Mexico, Pakistan, Paraguay, Tunisia and Uganda.

From 71 per cent in 1990, India now has 94 per cent of its population with access to drinking water sources, the report said.

The report, however, warned that the lack of progress on sanitation globally threatens to undermine the child survival and health benefits from gains in access to safe drinking water.

"Until everyone has access to adequate sanitation facilities, the quality of water supplies will be undermined and too many people will continue to die from water-borne and water-related diseases," said Maria Neira, Director of the WHO Department of Public Health, Environmental and Social Determinants of Health.