JERUSALEM - President Obama on Thursday finally uttered the words Palestinians had been waiting to hear for two years, that the basis for border talks with Israel should be the lines before the 1967 war, in which Israel captured big swaths of territory.

Now the question is whether this will be enough to get the Palestinians to drop plans to ask the U.N. General Assembly in September to recognize their state in the West Bank, Gaza, and East Jerusalem - areas Israel captured in 1967 - and instead return to talks with Israel.

Even if Palestinian Authority President Mahmoud Abbas were to choose the politically costly option of aborting the U.N. bid, the road to a resumption of talks, let alone a peace deal, would be long.

Abbas is to meet with leaders of the PLO and his Fatah movement Friday to decide on the next move, and senior officials would not speak to reporters before then.

Israeli Prime Minister Benjamin Netanyahu, en route to the United States, fired off a statement saying he would ask Obama during their White House meeting Friday what was meant by the reference to the 1967 lines - an idea rendered pliable by the president's caveat about "mutually agreed swaps" of land.

Obama's comments during his Mideast speech, marked a change in tactics for the president, said David Makovsky, an analyst at the Washington Institute for Near East Policy. Up to now, the administration had tried to summarize the positions of each party without taking its own position.

A U.S. official, speaking on condition of anonymity, said the new formulation, referring to the pre-1967 lines, was done in hopes of dissuading the Palestinians from going ahead at the United Nations.

"What was done today is that the U.S. took a descriptive position and turned it into a prescriptive position, setting new terms of reference, for new peace negotiations," Makovsky said. "It's a definite shift for the Obama administration, though not historically out of character for the U.S."

In 2000, President Bill Clinton had laid out parameters for a peace deal, proposing that the Palestinians keep all of Gaza and up to 96 percent of the West Bank, while Israel would annex areas where it has settled Jews in East Jerusalem and some Jewish settlements in the West Bank. The Palestinians would be compensated in a land swap.

Obama did not discuss the extent of the swaps. Netanyahu's predecessor, Ehud Olmert, sought to annex 6.5 percent of the West Bank, including some of the largest Jewish settlements, to Israel, and offered an equal amount of Israeli land in exchange.

Abbas would swap no more than 1.9 percent, which meant the vast majority of settlements would have to go.

Those talks broke off in 2008, and Netanyahu has since adopted a harder line.

For Netanyahu, as head of the right-wing Likud, it is a major leap that he is willing to state, as he did in Israel's parliament on Monday, that he would acquiesce to a Palestinian state in the strategic highland of the West Bank and in the coastal Gaza Strip.

But the Israeli leader still rejects a division of Jerusalem, wants to keep troops along the Jordan River on the Palestinian state's eastern flank, and wants to retain major blocs of Jewish settlements - almost certainly including the settlement of Ariel right in the middle of the northern West Bank.

In a statement Thursday, Netanyahu said he would ask Obama for a "reaffirmation" of commitments made by President George Bush in a 2004 letter to then-Israeli Prime Minister Ariel Sharon that "relate to Israel not having to withdraw to the 1967 lines, which are both indefensible."

Referring to Israel's settlements, Bush wrote: "In light of new realities on the ground . . . it is unrealistic to expect that the outcome of final status negotiations will be a full and complete return to the armistice lines of 1949" - a term synonymous with the pre-1967 borders.

The Obama administration has said it does not consider that letter binding.

"The basis has to be '67," said Marwan Kreidie, director of the Philadelphia Arab-American Development Corporation. "You can't allow illegal settlements to dictate the final deal. Will the Israelis be able to keep some of the main settlement blocs? That's possible, but it has to be done through negotiations."

It's not clear whether Obama's speech went far enough in coaxing the Palestinians back to talks. He did not call on Israel to halt settlement construction. He also said Israel must be "the homeland for the Jewish people," which precluded Palestinian demands for the "right of return" of Palestinian refugees and descendants to what is now Israel. And he questioned the impending entry into a Palestinian coalition of the extremist Hamas group.

Bassem Zbeidy, a Palestinian analyst, said the speech did not meet Palestinian expectations.

Philadelphian Bruce Ticker, an Israel-watcher and author of the blog JewishConcerns, felt the president was actually "punting" the problem to another day.

"The president is serious and no doubt wants a fair settlement," Ticker said. "But I got the feeling that he is just punting right now because there are a lot of problems associated with making any progress at all. I can't blame Israel for not wanting to negotiate when Hamas is involved, even indirectly, as long as their charter calls for the destruction of Israel."

Inquirer staff writer Michael Matza contributed to this article.