Israeli Foreign Minister Tzipi Livni warned Thursday against outside efforts to pressure Israel and the Palestinians to come up with a peace agreement this year, saying violence could erupt if they fail to meet international expectations.

The statement, coming on the eve of Secretary of State Condoleezza Rice's visit to Israel, effectively dooms the already slim chances that an Israeli-Palestinian peace agreement will be reached before President Bush leaves office in January.

Livni, Israel's chief peace negotiator and a top contender to be the next prime minister, said a timeline for a deal "is important, but what is more important is the nature and the content of the understanding that we can reach with the Palestinians."

"I believe we need to learn from past experience," she told foreign reporters in Jerusalem. "Any attempt to try and bridge gaps that maybe it's premature to bridge because of the international pressure . . . can lead to clashes, this can lead to misunderstandings and to violence."

The prospects for an agreement dimmed last month when Prime Minister Ehud Olmert, dogged by ongoing corruption investigations, announced that he will not seek reelection as head of his Kadima party in leadership voting next month. The move will effectively end his tenure as premier. Israel is unlikely to make any major decisions on concessions to the Palestinians until a new government is formed.

"There's absolutely no chance of reaching an agreement on anything by the end of the year," said Hirsh Goodman, a senior fellow at the Institute for National Security Studies at Tel Aviv University. "Usually I'm not prophetic, but there's no government on either side that can make any decisions on behalf of anyone."

For months, Livni has been meeting weekly with Palestinian chief negotiator Ahmed Qureia. She said they have been working toward an agreement on outstanding issues, including the final borders of a future Palestinian state, security arrangements, the status of Jerusalem and the right claimed by Palestinian refugees to return to homes inside Israel.

On the last issue, she said refugees must make their homes in a future Palestinian state.

"Israel is the homeland for the Jewish people, and the Palestinian state is to be the homeland for the Palestinians," she said. "What the Palestinians call the right of return is not an option. Without this understanding there is no agreement."

Palestinian negotiator Saeb Erekat issued a mild response to Livni's statement. "We're negotiating with Ms. Livni to reach a just and agreed solution on all issues," he said in a telephone interview. "I urge Ms. Livni to confine the negotiations to the negotiating room."

Livni said a peace deal could not be implemented while the armed Islamist movement Hamas controls the Gaza Strip, home to 1.4 million Palestinians. Palestinians view Gaza and the West Bank, where the Palestinian Authority holds sway, as the largest territorial components of their future state.

"Hamas represents an extreme ideology and is being supported by Iran," she said. "We need to continue to de-legitimize Hamas and to keep the pressure on Hamas."

Although there has been a truce between Israel and Hamas for the past two months, Livni said Hamas continues to stockpile weapons and build "a small army."