JERUSALEM — Israel is working with the United States to find a way to revive peace negotiations with the Palestinians in a desperate attempt to avert a diplomatic showdown at the U.N. next month, an Israeli official confirmed Tuesday.

The talks, meant to provide a framework for negotiations, are focusing on two of the most sensitive issues in the Israeli-Palestinian conflict: the borders between Israel and a future Palestine, and Israel's demand that the Palestinians recognize the country as the Jewish homeland.

Israel and the U.S. are making a painstaking effort to find language acceptable to all sides, the official said. While he said Israel is ready to show "flexibility" on the border issue, he acknowledged there was no imminent sign of a breakthrough. Palestinian officials said they were unaware of any new proposals.

Peace talks have been mostly stalled for nearly three years, and the Palestinians refuse to resume negotiations while Israel continues to build settlements in the West Bank and east Jerusalem. The Palestinians claim both areas, captured by Israel in the 1967 Mideast war, for their future state.

In the absence of a negotiated peace deal, the Palestinians plan to ask the United Nations to recognize their independence next month. The vote would be symbolic, but the Palestinians nonetheless hope it will isolate Israel and improve their negotiating position in the future.

Israel and the U.S. both oppose the U.N. bid, saying the conflict should be resolved through negotiations. Israel also fears the U.N. vote could spark street protests and potentially violent unrest.

The Israeli official said the two allies have been trying to devise a "package" that would allow talks to resume, and persuade the Palestinians to call off the U.N. initiative.

"Unfortunately, it has not been successful," the official said, speaking on condition of anonymity because he was discussing a sensitive diplomatic matter.

He said the U.S. is looking for Israel to endorse President Barack Obama's call for the borders of a future Palestine to be based on the pre-1967 lines between Israel and the West Bank, with some modifications based on negotiated land swaps.

In Washington, State Department spokesman Mark Toner declined to comment on the report that Israel agreed to negotiate on the basis of the pre-1967 cease-fire line. He also repeated U.S. opposition to the Palestinian U.N. initiative, adding that "we're working hard with both parties to find a way back to the negotiating table before then."

Prime Minister Benjamin Netanyahu has repeatedly said he will not return to the 1967 lines, and that he wants to retain chunks of the West Bank. But the official said Israel is "willing to show some flexibility" on the matter, if the Palestinians show flexibility with Israeli concerns.

Netanyahu has demanded the Palestinians recognize Israel as "the Jewish state," a position endorsed by Obama. The Palestinians reject this demand, saying it would undermine the rights of Israel's Arab minority as well as those of Palestinian refugees who hope to return to lost properties in Israel.

In the West Bank, senior Palestinian officials said they have heard nothing new from Israel or the United States.

"There is no offer," said Saeb Erekat, the chief Palestinian negotiator. "We have only heard things in the media. If Netanyahu would like to talk about accepting the 1967 borders, he can just show up and talk. But he is not serious."

The Palestinians are also demanding a halt to Israeli settlement construction before resuming talks. They say there is no point in negotiating if Israel continues to build homes in Jewish enclaves built on territories claimed by the Palestinians.

Some 500,000 Israelis live in the West Bank and east Jerusalem, including several thousand settlers living in West Bank outposts considered unauthorized even by Israel itself.

In a key ruling Tuesday, Israel's Supreme Court ordered the government to dismantle the largest of the more than 100 unauthorized outposts. The anti-settlement Peace Now group called it a landmark ruling.

In its decision, the court criticized the government for failing over the course of five years to come up with a program to evacuate Migron, as it agreed to do. It gave the government until March 31 to dismantle Migron, which is home to some 50 settler families.

Outposts are enclaves that settlers erected in an attempt to claim more West Bank land. The government has not authorized these outposts, but has often turned a blind eye while they were built.

Migron has become a symbol of settler defiance, and its evacuation seems likely to become violent.