By Laura Trevelyan
BBC News, United Nations, New York
The two sides wanting control of Western Sahara are to hold fresh talks brokered by the UN in New York.
Polisario kept up its war with Morocco until 1991
Morocco annexed Western Sahara in 1975, but the Algerian-based Polisario Front wants independence.
It is the latest round of talks to try to solve the frozen conflict. At the last round, in January, the UN said the two sides barely negotiated.
The former Spanish colony was divided between Morocco and Mauritania in 1975 - sparking war between the two states.
Morocco annexed the whole of the territory.
Fighting between Polisario and the Moroccan army ended in 1991 with a UN-brokered ceasefire, and the prospect of a referendum on the territory's future.
That has never happened. Morocco is offering Western Sahara greater autonomy - but Polisario wants a referendum on the future, with independence included as an option.
Algeria and neighbouring Mauritania will also attend the talks.