Eta also said on Thursday that its permanent ceasefire would go into effect later in the day, just after midnight.
"It is time to make important decisions, moving from words to deeds," Eta said in a new statement handed out to Basque newspaper Gara.
The group urged the French and Spanish governments not to thwart the process launched by its decision to lay down arms after nearly 40 years of bombings and shootings that have claimed more than 800 lives.
Much of Thursday's communique repeated wording contained in Wednesday's statement announcing the permanent ceasefire, a first for a group that has called truces before, only to revert to violence after peace talks failed.
But Thursday's document mentioned for the first time "dialogue and negotiation" with the governments of Spain and France.
France is included because the Basque region straddles the border, and Eta has traditionally said three regions of southwest France should be part of the independent Basque homeland it has been fighting to create.
"Eta calls on the authorities of Spain and France to respond in a positive way to the new situation and not place obstacles in the way of the democratic process," the statement said.
It did not say what issues should be negotiated.
The issue of the more than 800 Eta prisoners in Spanish jails is likely to be one of the topics Jose Luis Rodriguez Zapatero, the Spanish prime minister, will have to deal with.
Eta and its supporters have long demanded that Eta prisoners - intentionally spread around the country, sometimes in far-flung jails in the Canary Islands or Spanish enclaves in north Africa - be moved to the Basque region so that they can be closer to their families.
Zapatero has not decided if he
will engage in peace talks
Eta's weapons would also have to be dealt with.
Zapatero, who offered Eta peace talks last May if it renounced violence, has repeatedly said he would make no concessions to Eta and simply negotiate terms for its surrender.
He said after Wednesday's ceasefire announcement that he had not decided if the statement fulfilled his conditions for engaging in peace talks.
Hard line sought
The ceasefire was seen as a huge victory for the Socialist leader, but his critics maintained a hard line, saying they would fight to ensure that the government did not give too much away.
Mariano Rajoy, leader of the conservative opposition Popular Party, said: "One cannot pay a political price for peace. If we were to do so, terrorism would have won."
The European Commission also reacted cautiously on Thursday, calling Eta's announced ceasefire "an important development" but saying it was up to member governments to decide whether to remove it from the EU terrorist blacklist.
Rajoy called for the government
to maintain a hard line on Eta
"We see it as an important development, but it must first be evaluated by the Spanish authorities. It would be inappropriate to make a comment before the Spanish authorities," a spokeswoman said.
The news prompted a mix of wariness and jubilation across Spain, where ordinary citizens said they could hardly believe the end had come for a group blamed for so many deaths, injuries and an estimated $15.5 billion in damage.
Eta is believed to have been weakened by a series of arrests in recent years and stymied by the 11 March 2004 Madrid bombings blamed on al-Qaeda, which killed 191 people and wounded more than 1500 and made further Eta killing politically untenable.
Eta has not staged a fatal attack since May 2003.
The Basque group has been
blamed for more than 800 deaths
Commentators also linked the truce to the Spanish government's moves to hand more power to the northeast region of Catalonia, which would go some way to satisfying Eta demands.
Congress approved a new statute for Catalonia on Tuesday, recognising it as a "nation" in Spain - wording that horrifies patriots who see it as a first step in national disintegration.
The Basque Country has full autonomy over its finances and, like other regions, has a powerful regional government and responsibility for its own health and education services.
Eta's goal is for "self-determination" - understood as a call for a referendum and declaration of independence. Zapatero has ruled this out.