Desalination holds the solution to a looming shortage of clean water identified as a potential source of conflict in many parts of the world, experts said at a global conference in Singapore.

While 70 percent of the Earth's surface is covered with water, only three percent is fresh, and only 0.3 percent of the fresh water supply is accessible for human consumption, the conference was told.

But rapid advances in desalination technology, such as the use of membranes to convert sea as well as waste water into clean water, held the solution for many countries, experts at the International Desalination Conference said.

Singapore's Acting Minister for the Environment Lim Swee Say, in an opening speech, cited projections that in the next 25 years three billion people in 48 countries will face a shortage of fresh water.

By 2050, this will have increased to four billion people in 54 countries, meaning more than 40 percent of an expected world population of 9.4 billion will not have enough clean water, he said.

"These projections point clearly to the need for the global community to pay urgent and immediate attention to the global issue of fresh water supply," he added.

"There is a lot we can do to turn the abundant supply of seawater around us into fresh and potable water.

"We can do so with the use of membrane technology, a non-traditional water treatment method," he told the conference organised by the International Desalination Association (IDA) and timed to coincide with the UN-sponsored World Water Day.

IDA technnical program chairman Leon Awerbuch said that through desalination, purified water could be sold at cheaper prices to more people around the world.

The cost of purified water is seen to drop to 50 US cents per cubic meter in the next five years, from the current 70-80 US cents as more private enterprises build state-of-the art plants, he said

Middle East countries Bahrain, Saudi Arabia, Kuwait, Oman and the United Arab Emirates have almost total dependence on desalinated water, making the region a potential flashpoint in case of a water crisis.

These countries "cannot live without desalination anymore," he told reporters. "They have no choice. There are no rivers, no pipelines."

Without purified water, "they will have a major crisis and obviously they are all concerned about continuing supply of desalinated water and continuous growth in demand".

"So really, it is a critical issue to many countries in the world today," he said.

Consultancy PricewaterhouseCoopers in a report identified the Near and Middle East as having the greatest threat of conflict over water.

"Two-thirds of the water consumed in Israel comes from the occupied territories, while nearly half of the Israeli water installations are located in areas that were not part of it pre-1967," it said.

Friction between Lebanon and Israel rose sharply last week after the Jewish state accused its northern neighbour of seeking to divert water from a river that feeds the Sea of Galilee, Israel's prime source of fresh water.

Other flashpoints in the region are Turkey's plan to build dams to store the waters of the Tigris and Euphrates rivers, a scheme that is strongly opposed by Syria and Iraq; the Iraq-Iran row over the Shatt al-Arab waterway; and disputes over the use of water from the Nile, embroiling Egypt, Sudan and Ethiopia.