Hamas is prepared to offer a 50 to 60-year cease-fire if Israel withdraws to the 1967 lines, and is leaving open the possibility of an Israeli-Palestinian peace agreement in the distant future, Palestinian Prime Minister Ismail Haniyeh's political advisor told Haaretz.

But Ahmed Yusef said during an interview in his Gaza Strip office that such a peace deal has no urgency.

"It's possible to leave that matter for future generations," he said. "If we reach a long-term hudna [cease-fire] agreement, the future will show whether Israel wants to live in peace with the Palestinians. We do not plan to recognize Israel, since in any case it does not recognize the agreements it has signed."

Yusef, referred to in Palestinian newspapers as Haniyeh's "Weissglas," after the Israeli prime ministerial advisor Dov Weissglas, is considered close to Haniyeh. He is fluent in English and has some English books on his desk; he has written a few books himself. He wears a fashionable suit and a colorful tie, even though the local version of the galabiyeh, a gown worn by many men in the Middle East, is the most popular form of dress in the area.

According to Yusef, the concept of a long-term hudna is best for Israelis and for Palestinians at this stage. "You'll get the peace you're interested in while we can solve our internal problems," he said.

Yusef said Hamas is prepared to let Palestinian Authority Chairman Mahmoud Abbas negotiate on behalf of the Hamas government. "That's the job of the president," he said, using the Palestinian term for Abbas' position.

Yusef did not rule out the possibility that a future chairman from Hamas could also negotiate with Israel - "as long as it serves the Palestinian interest," he said. "We are also not opposed to our ministers' negotiating with your ministers on ongoing issues."

Yusef would not explicitly come out against Hamas' announcement that it plans to renew suicide bombings. He said the Palestinian government had no part to play in deciding whether to renew terror attacks, but said he didn't think terrorism would serve the government's purpose.

"Renewing the suicide bombings does not serve the interests of the Palestinian government," said Yusef. "The government is against harming civilians on both sides, and Prime Minister Ismail Haniyeh has acted decisively to stop civilians from being harmed, and even to stop rocket fire."

It was not clear whether Yusef was preparing an alibi of sorts for the government, in the event that Hamas does carry out another terror attack in Israel, or whether he was criticizing the decision to renew the terror attacks.

Hamas sources said that decision was made by the Hamas leadership in Damascus, but Yusef denied that the Damascus leadership was solely responsible. He said the decision was made by Hamas' military wing in the territories, with no connection to the political leadership.

"Israel is inviting the terror attacks," said Yusef. "Don't expect us to act like Christians. If they slap our cheek we will hit back, not turn the other cheek. If Israel escalates the fighting, it should not be surprised when the killing harms it as well."

Yusef also raised the issue of the deaths of seven members of a Palestinian family at a Gaza beach Friday: "Israel harms civilians, carried out a massacre on the coast and caused the Palestinian people to want a reaction."

He added, "There are many Palestinians who think we must not respond to Israeli crimes, in order to gain from publicity around the world. But the world was silent when it saw what Israel did."