Tony Blair stands ready to help cement the peace in Spain after Basque separatist group Eta announced it was laying down its arms, he said.
Talks like those in Northern Ireland are needed to consider issues such as decommissioning and the handling of prisoners, the former prime minister said.
Eta's historic announcement marked an end to four decades of bombings and shootings in which more than 800 people have been killed.
Mr Blair, who now has a central role in attempts to achieve peace in the Middle East as the Quartet envoy, said: "As in Northern Ireland, it is now necessary to address the consequences of the conflict by talks on decommissioning weapons, demobilising Eta, dealing with prisoners and exiles, and achieving security normalisation."
He said peace in Spain is crucial to the wider international community.
"I stand ready to help personally in any way I can," he said.
"The last armed confrontation in Europe is finally over. We should all welcome this and work together to make peace irreversible."