ANKARA, Turkey — A Kurdish militant group announced a historic decision Monday to disband and disarm as part of a new peace initiative with Turkey, after four decades of armed conflict.

The decision by the Kurdistan Workers’ Party, or PKK, was announced by the Firat News Agency, a media outlet close to the group. It comes days after it convened a party congress in northern Iraq.

In February, PKK leader Abdullah Ocalan, who has been imprisoned on an island near Istanbul since 1999, urged his group to convene a congress and formally decide to disband, marking a pivotal step toward ending the decadeslong conflict that has claimed tens of thousands of lives since the 1980s.

On March 1, the PKK announced a unilateral ceasefire, but attached conditions, including the creation of a legal framework for peace negotiations.

The group has led an armed insurgency since 1984 that has left claimed tens of thousands of lives. It is listed as a terror group by Turkey and its Western allies.

Firat news said the congress “decided to dissolve the PKK’s organizational structure and the end armed struggle, with the practical implementation of this process to be led and overseen by (Ocalan.) As a result, activities carried out under the name ‘PKK’ were formally terminated.”

Congress assessed that the PKK’s struggle had “brought the Kurdish issue to the point of resolution through democratic politics, thus completing its historical mission.”