The world's nations have achieved a UN goal of cutting in half the proportion of people without access to safe drinking water five years ahead of the 2015 target.
A report issued today by the UN children's agency and the World Health Organisation said more than two billion people gained access to safe drinking water between 1990 and 2010.
That means 89% of the world's population, or 6.1 billion people, had access to safe water sources at the end of 2010 - 1% more than the goal of 88% set by world leaders at the UN Millennium Summit in 2000, the report said.
But the report said 783 million people still have no ready access to safe water.
The UK's International Development Secretary, Andrew Mitchell, said: "This is concrete proof that well-spent aid can make a real difference to the lives of the some of the very poorest.
"There is still much more to do. Millions of the world's poorest people still have no access to either a tap or a lavatory.
"Providing clean, safe water and sanitation remains a top priority. That is why Britain has refocused its aid to areas with the worst access to clean drinking water, sanitation and hygiene."