The United States, China, India must commit themselves to take action against global warming to ensure that more people will have clean water, Swedish Prime Minister Fredrik Reinfeldt told the opening session of World Water Week today in Stockholm.

Controlling climate change is necessary to make the most of an increasingly scarce resource, the prime minister said, urging the completion of a successor agreement to the Kyoto Protocol by the end of 2009, when Sweden holds the presidency of the European Union.

This year, 150 different organizations are involved in arranging seminars, side-events, meetings and workshops under the theme, "Progress and Prospects on Water: Striving for Sustainability in a Changing World."

More than one billion people still live without a safe water supply, and half the developing world does not have basic sanitation, Berntell reminded participants. He warned that the UN's Millenium Development Goals for water and sanitation will not be met by 2015 unless better progress is made.