But Mr. Obama did not plan to present an American blueprint for peace, White House officials said, and it remained unclear if he would even endorse a Palestinian state on pre-1967 lines, a move opposed, administration officials said, by his chief Middle East adviser, Dennis Ross. Mr. Obama did seek to increase pressure on Syria by imposing largely symbolic sanctions on its leader, President Bashar al-Assad, in the wake of the bloody crackdown there.

White House officials declined to say whether Mr. Obama would go further in Thursday’s speech and call on Mr. Assad to resign.

The debate around Mr. Obama’s remarks, which the White House has billed as a major address, is made even more significant since the president’s speech will serve as the beginning of what promises to be several intense days of debate over American policy in the region, its support for Palestinian statehood, and how far Mr. Obama is willing to push Israel on peace with the Palestinians at a time of upheaval in the region. Mr. Obama is to meet with Mr. Netanyahu the day after his speech, on Friday. Two days after that, Mr. Obama is scheduled to address the American Israel Public Affairs Committee, the pro-Israel lobby. Next week, Mr. Netanyahu will counter with his own address to a joint meeting of Congress.

Mr. Netanyahu, aides say, is planning to tell Mr. Obama that Israel wants to keep a military presence along the Jordan River and sovereignty over Jerusalem and the settlement blocs — three major stumbling blocks for the Palestinians — but that it would be willing to negotiate away the rest of the West Bank, more territory than Mr. Netanyahu has been willing to specify in the past. He has one condition — the Palestinian government cannot include Hamas. Mr. Netanyahu knows that the Palestinians will find this condition unacceptable, particularly since Fatah, the main Palestinian movement, just signed a unity pact with Hamas. But since the United States labels Hamas as terrorists, Mr. Netanyahu is betting that he will appear more forthcoming than ever.

“On the one hand, the Palestinians are moving toward Hamas while on the other, the prime minister is showing a real willingness to make far-reaching territorial compromise,” a top Netanyahu aide said, speaking on condition of anonymity.