JERUSALEM (AFP) - Israeli Foreign Minister Tzipi Livni on Thursday played down US-backed hopes of a peace deal with the Palestinians this year, saying that a premature agreement could trigger new violence. "There is some kind of expectation of doing something before the end of the year," she said in reference to statements made by all sides at a US-sponsored conference that revived the long-dormant peace process last Nov. "I believe that the timeline is important but what is more important is the content and the nature of the understanding that we can reach with the Palestinians," Livni said at a news conference with foreign journalists. "I think any attempt to bridge gaps which might be premature to bridge or any attempt to reach something which is not the comprehensive agreement we want to reach can lead... to clashes, this can lead to misunderstandings, this can lead to violence," she said. "Until everything is agreed, nothing is agreed," said Livni, who heads the Israeli negotiating team in the peace talks and hopes to replace Prime Minister Ehud Olmert when he steps down after elections for the leadership of their centrist Kadima party in mid-September. She also acknowledged that even if an agreement is reached, it might not be implemented as long as Hamas controls the Gaza Strip."The question of how long it should be on the shelf depends not on our willingness but on the situation on the ground," said Livni. She insisted that Hamas cannot be included in negotiations. "This is the reason we negotiate with pragmatic leaders even though they don't control anything in Gaza Strip, which is being controlled completely by Hamas. Even in the West Bank they are not strong enough," Livni said.But she stressed that negotiations "with pragmatic leaders" were not enough in themselves. "We have to delegitimise Hamas." "When we are talking two states for two people, the idea is Israel is the homeland for the Jewish people and the Palestinian state is the homeland for the Palestinians," Livni said. "Without this concept, there is no agreement," she said, adding: "This is one of the two basic pillars... the other of course is Israel's security.""What the Palestinians call the right to return is not an option," she said. In response Abbas' spokesman Nabil Abu Rudeina claimed Livni's warning about any premature agreement amounted to "an Israeli attempt to avoid reaching an accord." He also criticised her position on Palestinian refugees, and urged Israel to "adopt a responsible position and not to waste time."