Defense Minister Ehud Barak declared Sunday that Prime Minister Benjamin Netanyahu would have to "make some difficult decisions" in order to advance the Middle East peace process, urging the government not to miss out on this chance for a settlement.

The defense minister's remarks came hours after Netanyahu met with U.S. special Mideast envoy George Mitchell in Jerusalem, and as the Palestine Liberation Organization approved a proposal to launch indirect peace negotiations under U.S. moderation.

"I hope that these discussions will advance the political process with the Palestinians in a manner that will enable a quick resumption of actual negotiations on core issues that will result in an agreement," said Barak, who met over the weekend with Mitchell.

"This goal has slipped away from us time after time for almost 20 years," added the defense minister. "Israel's leaders today have the responsibility to ensure that we don't miss this chance, and that requires leadership and the intention to make difficult decisions."

Palestinian President Mahmoud Abbas would have to make the same decisions on behalf of his own people, said Barak, "and so will Prime Minister Netanyahu."

PLO okays indirect talks, seeks results in months

The PLO's executive committee on Sunday approved a proposal allowing the Palestinian president to begin indirect negotiations with Israel through U.S. mediation, effectively ending a 14-month breakdown in communications between the two sides.

Palestinian officials warned, however, that they would walk away if the outlines of a border deal with Israel have not emerged after four months. They also ruled out subsequent direct talks without a complete Israeli settlement construction freeze.

"This peace process cannot go on forever," said Palestinian negotiator Saeb Erekat. "Now it's time for decisions."

Erekat said he did not know when the indirect talks would begin.

Abbas has declared refusal to negotiate directly as long as Israel continues to build in its settlements in East Jerusalem and the West Bank. He sought final authorization from the top decision-making body to allow him to resume indirect peace talks with Israel, at the U.S. initiative.

Sunday's decision by the PLO leadership was expected after the Arab League gave the Palestinians political cover last week by approving the concept of indirect talks.

Mitchell and Netanyahu meet in Jerusalem

The announcement was made as the U.S. mediator, George Mitchell, held a four-hour meeting in Jerusalem with Netanyahu. The two will meet again on Monday, after which Mitchell will head off to Ramallah to for talks with Abbas.

"If there is a desire to get to direct talks through a corridor then I think the sooner the better," Netanyahu, referring to U.S.-mediated "proximity talks", told reporters at the start of his meeting with Mitchell.

Mitchell said he hoped for a "credible, serious, constructive process" leading to comprehensive peace in the Middle East.

A brief statement issued by Netanyahu's spokesman after the session said the Israeli leader and Mitchell "had a good conversation ... on moving the diplomatic process forward". The statement did not reveal whether the two had reached an agreement on the tangible resumption of talks, which the United States has offered to mediate.

Both the PLO and the Arab League have expressed skepticism about Israel's intentions, but said they want to give U.S. mediation a chance.

Renewed talks would mark U.S. President Barack Obama's first success in the Israeli-Palestinian arena. In coming months, Mitchell is expected to shuttle between Abbas' headquarters in Ramallah and Netanyahu's office a half hour away in Jerusalem.

The Palestinians broke off the talks when Israel launched its offensive in the Gaza Strip in December 2008 to stop daily rocket fire from the coastal territory.

Netanyahu has said he prefers direct peace talks, but would accept mediated negotiations.

For more than a year, the Obama administration has been laboring to get both sides negotiating again, disappointed to discover that its plan to fast-track peacemaking would be frustrated by deeply rooted conflicts and domestic politics.

The U.S.-mediated talks are expected to focus on guidelines for discussing the key issues that have divided Israelis and Palestinians for decades: final borders, the fate of millions of Palestinian refugees, and a resolution to the rival claims to Jerusalem.

Palestinians: Talks must focus on borders

Yasser Abed Rabbo, a PLO spokesman, said Sunday that the indirect talks should focus on drawing a border between Israel and a future Palestinian state.

Netanyahu, who leads a hawkish coalition, takes a harder line on territorial concessions than his predecessor, Ehud Olmert, with whom Abbas failed to reach an agreement in 2008.

In November, under heavy U.S. pressure, Netanyahu persuaded his Cabinet to authorize an unprecedented 10-month settlement construction slowdown. But Israel continues to build 3,000 apartments that were authorized before, and construction in east Jerusalem has not been restricted.

Netanyahu has also riled Palestinians recently by placing two West Bank shrines on Israel's register of national heritage sites and declaring that Israel would insist on retaining a presence in the West Bank valley that borders Jordan under a final peace deal.

In the past, failed talks have touched off years of violence.