An internationally-backed conference taking place in the Basque Country in Spain on Monday is being seen as a possible prelude to the final dissolution of ETA.
Co-operation between Spain and France has greatly weakened the group in recent years.
Last month, hundreds of ETA prisoners urged other members still at large to end their four decades of violence.
Former Irish PM Bertie Ahern and Sinn Fein president Gerry Adams will be at the conference in San Sebastian.
They will share their experience of the ending of the Northern Irish conflict.
Former UN chief Kofi Annan is those attending the talks.
ETA is listed as a terrorist group by Spain, the EU and the United States.
In January, it declared a permanent ceasefire - but the BBC reports such ceasefires have been broken before.
A ''permanent ceasefire'' declared in March 2006, was broken nine months later when a bomb was planted in a Madrid airport car park. Two people were killed.