Mali's military rulers announced late Thursday the "end, with immediate effect" of a key 2015 peace deal signed with northern separatist groups, following months of hostilities between rebels and the army.

The junta blamed the "change in posture of certain signatory groups" but also "acts of hostility" by the lead mediator Algeria, government spokesperson Colonel Abdoulaye Maiga said in a televised statement, on ending a deal considered essential in maintaining stability in a country rocked by jihadist violence since 2012.

Algeria was the main mediator in efforts to return peace to northern Mali following the agreement signed in its capital in 2015 between the Malian government and predominantly Tuareg armed groups.

It was considered by many analysts to be crucial for stabilising Mali, a poor and landlocked country in West Africa.

But the deal had already begun to unravel last year, when fighting between the separatists and Mali government troops broke out in August after eight years of calm, as both sides scrambled to fill the vacuum left by the withdrawal of United Nations peacekeepers.

Mali's military leaders, who seized power in a 2020 coup, ordered the departure of the UN's MINUSMA mission last June, accusing the troops of "fuelling community tensions".

It also broke off relations with former colonial power France, which had been helping to fight jihadist insurgents in the north, and since then has turned to Russia for political and military assistance.

The separatist rebels, grouped under the Coordination of Azawad Movements (CMA), had already accused the military junta in July 2022 of its "abandonment" of the pact.

Mali's rulers, meanwhile, said neighbouring Algeria was hosting on its territory representative offices for some of the separatist groups that signed the deal, some of which had become "terrorist actors".

Maiga denounced "a misperception by the Algerian authorities, which consider Mali their backyard or a doormat, against a background of contempt and condescendence".

In December, Mali summoned the Algerian ambassador over what it called "interference" and "unfriendly acts", accusing the diplomat of holding meetings with Tuareg separatists without involving Bamako.

The Algiers agreement had called for the integration of ex-rebels into the Malian defence forces as well as greater autonomy for the country's regions.

Maiga said Mali's government "notes the complete impossibility of the deal... and in consequence announces its end, with immediate effect".