The Basque separatist group Eta has said the peace process that began in March, when it declared a permanent ceasefire, is now in crisis.
Demonstrations by Eta supporters are banned
In a statement to the Basque newspaper Gara, Eta threatened a response if Spain and France continued their "repressive" policy towards Eta.
It accused the Socialist government in Madrid of reneging on an agreement not to arrest any more Eta members.
Madrid denies having made any such promise.
"If the attacks against the Basque country continue, Eta will respond", Eta warned.
In June, Spanish Prime Minister Jose Luis Rodriguez Zapatero announced in parliament that his government would open talks with Eta, which is pressing for Basque independence.
But he said that "democracy will not pay any political price to achieve peace" with Eta and he did not give a date for the start of talks.
In its statement - the fifth since it declared ceasefire five months ago - Eta accused the ruling Socialist party and the Basque Nationalist Party, which governs the troubled region, of delaying tactics.
Spanish analysts say that Eta is frustrated with the Spanish government's refusal to include its political wing, Batasuna, in all-party talks before it publicly renounces violence.
Batasuna was banned in 2003 because it refused to condemn violence by Eta.
More than 800 people have been killed since 1968, when Eta took up arms to press for independence for the Basque country, but the group has not killed anyone for more than three years.