Algeria has suspended its 20-year-old cooperation treaty with Spain, the country's presidency announced Wednesday.

The decision came after Madrid reversed its long-standing policy of neutrality on the Western Sahara conflict in March by backing Morocco's position.

What did Algerian officials say?

"Algeria has decided to immediately suspend the treaty of friendship, good neighborliness and co-operation" signed with Madrid in 2002, the president's office said in a statement.

Algeria said it considered Spain's "unjustifiable" change of position to be contrary to international law, directly contributing to a degrading situation in the vast, mineral-rich region.

"The current Spanish government has given its full support to the illegal and illegitimate form of internal autonomy advocated by the occupying power, and has worked to promote a colonial fait accompli using spurious arguments," the Algerian president's office said, as quoted by Spanish news agency EFE.

In March, Algiers withdrew its ambassador in Madrid.

Madrid 'regrets' move by Algeria

In a short statement, the Spanish government said it "regrets" Algeria's decision to suspend the bilateral treaty.

Madrid said it "considers Algeria a neighboring and friendly country and reiterates its full availability to continue maintaining and developing the special relations of cooperation between the two countries."

It also reiterated Madrid's commitment to the principles of the treaty, citing those of "sovereign equality of states, non-interference in internal affairs and respect for the inalienable right of self-determination."

The Spanish-Algerian treaty sought to strengthen political dialogue between the two countries at all levels, and to promote the development of cooperation in the economic, financial, educational and defense fields.

Spain also relies on Algeria for its natural gas supply.

What is Spain's stance on the Western Sahara?

In a bid to end a diplomatic crisis with Morocco, Spain in March publicly recognized Rabat's autonomy plan for the disputed region.

Madrid has traditionally supported United Nations agreements to hold a referendum in the territory, which is a former Spanish colony.

Morocco and Algeria are direct rivals in the rule of Western Sahara, 80% of which is controlled by Morocco. Algeria is the principal supporter of the Polisario Front independence movement, which controls the remaining territory. The Polisario demand a referendum on independence in the region, and have battled a 15-year war with Morocco.

In August last year, Algiers broke off diplomatic ties with Rabat over "hostile acts."

aw/rs (EFE, dpa, AFP, AP)