ULAN BATOR (AFP) – Expanding deserts "suffocate livelihoods and a way of life," UN Secretary General Ban Ki-Moon said on Monday in Mongolia, on a visit to highlight the risks posed by desertification to one third of the world's population.

"You are part of the one third of the world's population -- two billion people -- who are potential victims of desertification," Ban told the landlocked country's parliament, in a speech on overcoming the challenge of climate change.

On Sunday, Ban met with herders to see first-hand how their lives were being affected by water shortages and the encroaching Gobi desert.

Earlier on Monday he had discussed with Mongolian leaders how to address climate change issues and secure food supplies in vulnerable areas.

The theme of Ban's visit to Mongolia is the importance of helping communities adapt to the effects of climate change so they can become more resilient in the face of extreme weather and other environmental problems.

He commended the Mongolian government on its efforts to better manage grasslands and pastures and for programmes such as improved weather forecasting and insurance funds aimed at protecting herders' livelihoods.

Growing livestock populations and deteriorating pastureland in Mongolia threatened to exacerbate severe weather conditions, the World Bank warned earlier this month.

Ban's visit to Mongolia comes less than a week after rain storms triggered the country's worst flooding since 1966, according to the Red Cross.

More than 20 people died and around 120 homes were destroyed -- a stark reminder of the extreme weather conditions that add to the woes of one of the poorest countries in Asia.

Mongolia's grassland is rapidly turning into desert, the environmental ministry warned last month.

Grassland is thinning in three quarters of the country, while seven percent of the steppe has already become desert.

Ban has said he will host a summit in September on the sidelines of the UN General Assembly to galvanise support for a global deal in Copenhagen in December on "a fair, effective and scientifically ambitious new climate framework".

Negotiations to seal a climate change treaty have been dogged by disagreements over targets for cuts in carbon emissions and a fund from rich nations to help developing countries tackle climate change.

The planned treaty, due to take effect from 2013 as the successor to the Kyoto Protocol, will shape worldwide action on the issue up to the middle of the century.

Ban travelled over Mongolia's open steppe on Sunday to meet a community of nomadic herders in a region called Bayansonginot.

"He wants to learn from the people who are dealing with climate change. The solutions are not going to come from the scientists," Ban's spokeswoman Michele Montas told AFP.

Inside a traditional ger, or yurt, Ban discussed the community's challenges with the head of the household, Mamo Batchuluun.

"We are involved in an environmental project to protect the nature of this area. We are trying to prevent desertification of the land," Batchuluun said.

The community is part of a Netherlands-funded programme that is helping find new sources of income, such as growing vegetables and making felt handicrafts, while preserving the grasslands.