The disputed region of Western Sahara in northwestern Africa is straining ties between Algeria and Spain.
The Algerian government has suspended a friendship agreement and halted all trade except for natural gas for now.
Western Sahara was a Spanish colony until 1975. Morocco then took control in a move that has not been recognised internationally.
Algeria supports the Polisario Front, which has been fighting for independence in Western Sahara.
In March, Spain’s Prime Minister Pedro Sanchez angered Algeria when he joined a growing number of countries endorsing Morocco’s plan to give the region some autonomy.
Can one of the world’s longest-running conflicts ever be resolved?
Presenter: Nick Clark
Sidi Omar – Polisario Front representative at the United Nations
Yasmine Hasnaoui – North Africa affairs specialist
Riccardo Fabiani – project director for North Africa, International Crisis Group