The United Nations envoy to Western Sahara says the status quo in the disputed Moroccan territory is untenable.

Western Sahara -- one of the word's most sparely populated hinterlands -- is also some of its most hotly-contested turf, with no less than three countries implicated in local demands for independence from neighboring Morocco.

For nearly 20 years, a ceasefire has kept separatists and Moroccan soldiers at a distance, across a 2,700 kilometer wall of sand.  However, in neighboring Algeria yesterday, U.N. Special Envoy Christopher Ross said that this peace will be impossible to retain.

Ross says there is no doubt that the status quo is untenable, in the long term, considering the costs and the dangers it comes with.   He says the parties must now show proof of their political will, which is necessary to move ahead.

The Moroccan government maintains that the 1,000 kilometer stretch of Saharan seaboard is an integral part of its historical territory and that has been its unchanging policy since Spain let go of Western Sahara  in 1975.

Mauritania, too, has at times laid claim to the land.

And, an Algerian-backed rebellion wants to administer the province as free nation.

Ross says, If any of these parties are seriously committed to peace, all four disparate and competing interests must be more flexible at the negotiation table.

He says progress demands negotiations without pre-conditions and, in good faith to achieve a just, lasting political solution that will be mutually acceptable and will provide for the self-determination of the people of Western Sahara.

Ross says he is scheduled to visit Mauritania and Morocco in coming weeks, as his office plans a third round of informal talks in November.

He says he hopes to see the parties emerge from the ongoing impasse and begin intensive and substantive negotiations on the future of Western Sahara

The country of just 500,000 citizens is thought to hold possibly exploitable oil reserves, like those found in neighboring Mauritania.  But those deposits remain unexplored as international law and opinion has hindered investment in the country's potentially vast natural resources.