The Aral Sea, once the world's fourth largest lake, has in recent decades shrunk in size by more than 70 per cent after tributary rivers were diverted for irrigation projects. The salinity of the region's soil has soared and the area is also heavily polluted.

“It was shocking,” Mr. Ban told reporters in Nukus after a helicopter tour of the area with Prime Minister Shavkat Mirziyoyev of Uzbekistan, the latest stop on his visit to Central Asia.

“It is clearly one of the worst environmental disasters of the world... It really left with me a profound impression, one of sadness that such a mighty sea has disappeared,” he stated.

The Secretary-General said that, standing on the shores of a vanished sea, he could not see anything except a “cemetery of ships marooned in the sand.” As a result of the disaster, people are getting sick, the land is poisoned, and storms blow dust and salt as far as the North Pole.

“It was a vivid testament to what [...] happens [...] when we waste our common natural resources, when we neglect our environment, when we mismanage our environment.”

Speaking later at an official dinner in the capital, Tashkent, the Secretary-General noted that the aerial tour reminded him of flying over Africa's Lake Chad in 2008. “It, too, has shrunk to a small fraction of its former size, with disastrous effects on millions of people.

“I think this is a collective responsibility, not only for the nations of Central Asia but the whole world,” he said. “I was very encouraged by what I learned? all the measures the Government is taking to deal with the effects of the disaster.”

Mr. Ban voiced appreciation for the international fund for saving the Aral Sea which was initiated by the five leaders of Central Asia, and pledged the UN's assistance for their efforts.

“We should become better stewards in managing the environment,” Mr. Ban stated. “We must deliver this Planet Earth to our succeeding generations, so that they can live in a more hospitable, in a more environmentally sustainable way.

“That is a moral and political imperative,” he stressed.

While in Tashkent, the Secretary-General will meet tomorrow with President Islam Karimov and deliver a lecture at the University of World Economy and Diplomacy.

Mr. Ban's first official visit to Central Asia since becoming UN chief also included stops in Turkmenistan and Kyrgyzstan, and will take him next to Tajikistan and Kazakhstan.