President Obama’s endorsement on Thursday of using the 1967 boundaries as the baseline for a solution to the Israeli-Palestinian dispute — the first by an American president — prompted Prime Minister Benjamin Netanyahu of Israel to push back testily and the Palestinian leadership to call an urgent meeting.

Mr. Netanyahu said in a pointed statement just before boarding a plane to Washington that while he appreciated Mr. Obama’s commitment to peace, he “expects to hear a reaffirmation from President Obama of American commitments made to Israel in 2004 which were overwhelmingly supported by both Houses of Congress.”

Those commitments came in a letter from President George W. Bush which stated, among other things that “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,” another way of describing the 1967 boundaries.

Mr. Netanyahu, who is to meet with Mr. Obama at the White House on Friday in what seems likely now to be a tense encounter, added that the commitments “relate to Israel not having to withdraw to the 1967 lines, which are both indefensible and which would leave major Israeli population centers in Judea and Samaria beyond those lines,” a reference to large Israeli settlement blocs in the West Bank.

Mr. Netanyahu said in Parliament on Monday that Israel needed to hold on to the large settlement blocs in any two-state solution with the Palestinians.

Mr. Obama’s new position does not appear to rule out Israel’s retaining settlements. But it suggests that the United States would back the Palestinian position that a solution should be close to the 1967 lines and that any retained land would be compensated with other land, which is one reason Mr. Netanyahu’s government firmly opposes the change in position. Dore Gold, a former Israeli ambassador to the United Nations and a confidant of Mr. Netanyahu’s, lamented by telephone that Mr. Obama’s speech was “a radical shift in United States policy towards Israel.”

He said the 2004 letter was endorsed not only by a strong bipartisan majority but by Hillary Rodham Clinton, then a New York senator. “By mentioning the 1967 lines today, President Obama is going back on what had been an American commitment less than a decade ago,” he added.

In the West Bank city of Ramallah, Saeb Erekat, the chief Palestinian negotiator, issued a general statement of appreciation for “efforts being exerted by President Obama with the objective of resuming the permanent status talks in the hope of reaching a final status agreement on all core issues, including Jerusalem and refugees and within a specified time frame.”

He added that President Mahmoud Abbas of the Palestinian Authority “decided to convene an emergency session for the Palestinian leadership as soon as possible and he will consult with our Arab brothers at the same time.”

He and other officials declined further comment.

Khalil Shikaki, a Palestinian political scientist and pollster, said the Obama speech had created a new situation because it was the first time that a president had declared it to be American policy for the 1967 lines to be the basis for a solution.

“This is much tougher for Israel to swallow, and definitely this is a point which Netanyahu, if he didn’t intend to address in his trip, is now being forced to do so,” Mr. Shikaki said. “And if he doesn’t, he will find himself further isolated.”

Yossi Beilin, a longtime peace negotiator for Israel and a former government minister who is now in private business, said by telephone that what Mr. Obama said was a “historic precedent.” He said that President Bush had spoken about ending the occupation that began in 1967, but that Mr. Obama’s formulation suggested an equal exchange of territory in a final deal.

Mr. Obama stated that the solution should be based on the 1967 lines with mutually agreed land swaps, meaning that if, as expected, Israel held on to some close-in settlements, it would have to yield an equal amount of land to the future state of Palestine from within its borders.

This formulation goes beyond what President Bill Clinton called for in 2000 and is in keeping with one of two key Palestinian demands for a return to direct peace negotiations. The other is at least a temporary freeze in Israeli settlement building, which Israel has rejected. Whether the Palestinians could be persuaded to return to talks with only one of their two conditions met was unclear.

But Mr. Abbas has made clear that he would prefer negotiations over an appeal to the United Nations this September, the other path he has been pursuing. That path would help the Palestinians gain legal advantage over Israel but it could also lead to unmet expectations in the streets of the West Bank once it became clear that United Nations recognition did not rid the area of Israeli occupation. That could result in frustration and violence.

If Mr. Netanyahu was upset by the president’s reference to 1967, politicians to his right — who make up the bulk of his party and his governing coalition — were horrified.

Danny Danon, a member of Parliament from Mr. Netanyahu’s Likud party, said: “With his call for Israel to return to 1967 borders before the Palestinians even sit down at the negotiating table, it is now clear that the U.S. president has adopted Yasir Arafat’s infamous ‘Stages Plan’ and the hope to eventually remove the State of Israel from the map. I call on Prime Minister Netanyahu to unequivocally state to the president tomorrow that this vision will never be implemented as it is in direct opposition to the security and strategic interests of the people and land of Israel.”

An Israeli official who spoke on the condition of anonymity because he had not been authorized to speak, said there was much in the president’s address that would please Israeli ears.

In particular, he said, Mr. Obama put the onus on the Palestinians to make sure that the recent unity pact between Fatah and Hamas not torpedo the possibility of peace by insisting that Hamas renounce violence. He also told the Palestinians not to try to isolate Israel at the United Nations or deny Israel’s existence. And he rejected the campaign to delegitimize Israel.

On the other hand, Mr. Obama spoke of a “full and phased withdrawal of Israeli military forces,” meaning he seemed to distance himself from Mr. Netanyahu’s desire to keep Israeli troops along the Jordan River in a future Palestine.

Much of the initial Palestinian reaction to the speech was dismissive. Mahmoud Zahar, a Hamas leader in Gaza, called it a pure adoption of the Israeli perspective. “Obama tries to give an impression that it is Israel which seeks negotiations and peace, not the Palestinians,” he said.

Daoud Netwali, 54, watched the speech in his home in the Aija refugee camp near Bethlehem. Afterward he said: “I don’t trust the speech. If Obama wanted to do something for the Palestinian people he should have done it already. Obama and Clinton and Bush are all the same. They say things on TV but they don’t do it on ground.”