Algeria has concluded a 20-year friendship agreement with Spain, which provided for the two countries to co-operate in controlling migration waves, escalating disputes over Madrid's stance on Western Sahara.

Algerian state media reported the decision without giving reasons.

Spanish diplomatic sources confirmed Algeria's decision, expressing regret and reaffirming their commitment to the agreement.

The 2002 agreement forced the two sides to "deepen co-operation in controlling migration flows and combating trafficking in human beings," according to a text published in Spain's official newspaper,

reports .

Algeria was outraged when Spain announced in March that it supported Morocco's plan to grant autonomy to Western Sahara.

Algeria backs Polisarion, the Sahara independence movement that Morocco considers its own and the government's.

Algeria, meanwhile, is a major gas supplier to Spain, but Algerian President Abdelmadjid Tebbeoune said earlier that he would not terminate the supply contract for diplomatic reasons.

The Spanish foreign minister said Wednesday that there were no indications that Algeria could take measures that would affect gas supplies following the breach of a 20-year agreement on friendship, good neighborly relations and co-operation with Spain.

The Algerian government is a reliable partner and has given Spain guarantees from the highest levels regarding gas supplies, Spanish Foreign Minister Jose Manuel Albares told reporters.

Algeria is expected to change prices when it concludes new gas supply contracts with Spanish companies.

Under the current contract, which is long-term, Algeria supplies gas at prices below market prices, said the same source, who wished to remain anonymous.