President Mahmoud Abbas said on Tuesday Palestinians could take unilateral steps if Israel does not agree to halt settlement building in the occupied West Bank and recognise the borders of a future Palestinian state.
Speaking ahead of talks in Jordan between Israeli and Palestinian negotiators, Abbas said Palestinians were ready to take difficult measures, but did not specify what they were.
Negotiators from the two sides were due to meet in Amman later on Tuesday alongside international mediators trying to revive their stalled peace talks, but neither side is raising hopes they can end more than a year of deadlock.
Negotiations foundered in late 2010 after Israel refused to renew a partial freeze on Jewish settlement in the occupied West Bank, as demanded by Palestinians.
The Palestinians say they cannot hold talks while Israel cements its hold on land it captured in a 1967 war and on which they intend to establish an independent state. Israel says peacemaking should have no preconditions.
Abbas said that if Israel agreed to halt settlement building and recognise the vision and borders of the two-state solution, Palestinians would agree immediately to negotiations.
If they don't ... there are measures that we could take. But we will not declare them now because they have not been finalised. But we will take measures that could be difficult, Abbas told a group of judges in Ramallah.
He said the two sides had until January 26 to make progress. The date marks the three-month deadline, agreed on October 26, for them to make proposals on issues of territory and security, with the aim of reaching a peace deal by the end of this year.
Israeli cabinet minister Dan Meridor said that although the meeting could present a chance to revive the peace talks, the onus on moving ahead should not be put squarely on Israel.
There is an opening to renew negotiations... We must hope that things will work out but it does not depend only on us, Meridor said.
The talks at the Jordanian Foreign Ministry bring together Palestinian negotiator Saeb Erekat, Israel's Yitzhak Molcho and representatives of the Quartet of Middle East mediators - the United States, European Union, Russia and the United Nations.
Jordan, which signed a peace treaty with Israel in 1994 and has strongly backed Abbas, is worried the failure to address core issues at the heart of the conflict could bring a renewed cycle of violence that could endanger its own security.
The majority of Jordan's population are Palestinians descended from those displaced during successive Arab-Israeli wars since the Jewish state's founding in 1948.
Our objective is to bring them together and try to push for a breakthrough in peace talks to arrive at addressing final status issues, starting with borders and security, Jordanian Foreign Minister Nasser Judeh said.
A senior figure in Abbas's umbrella PLO executive said Israel and the Palestinians were simply fulfilling a request by the Quartet to present their positions on security and borders.
This is not a resumption of negotiations, Wasl Abu Yossef told Reuters in Ramallah, the seat of Abbas's administration.
A diplomat in Amman also said Tuesday's meeting was not expected to lead to a breakthrough. To be realistic, it won't solve anything, (although) it could give new energy to the process, the diplomat said.
Established a decade ago, the Quartet has in recent months taken a leading role in attempts to broker new negotiations, stepping in after U.S. President Barack Obama's administration failed to revive diplomacy.
Most countries deem Israel's West Bank settlements illegal. Israel disputes this, and says it would keep settlement blocs under any peace deal in accordance with understandings reached in 2004 with then-U.S. president George W. Bush.
Prime Minister Benjamin Netanyahu's government criticises Abbas for seeking a reconciliation with the Islamists of Hamas, who control Gaza and reject permanent co-existence with Israel.
Abbas has also balked at Israel's demand that he recognise it as a Jewish state.
(Additional reporting by Ori Lewis in Jerusalem and Jihan Abdalla in Ramallah; Writing by Dominic Evans; Editing by Mark Heinrich)