Prime Minister Benjamin Netanyahu yesterday rejected U.S. President Barack Obama's call for the borders of a Palestinian state to be based on the pre-1967 armistice lines, saying Israel could not accept a withdrawal to "indefensible" borders.

In a speech outlining U.S. policy in the Middle East, given a day before Netanyahu arrives in Washington, Obama officially adopted the Palestinians' position. "We believe the borders of Israel and Palestine should be based on the 1967 lines with mutually agreed swaps, so that secure and recognized borders are established for both states," he said.

Until yesterday, the U.S. position had been that the Palestinian goal of a state based on the 1967 lines should be reconciled with Israel's desire for defensible borders.

In a statement issued after the speech, Netanyahu said, "the viability of a Palestinian state cannot come at the expense of the viability of the one and only Jewish state." A withdrawal to the 1967 lines would not allow Israel to defend its major population centers, he explained, reiterating his demand that Israel keep the major settlement blocs and maintain an Israeli military presence in the Jordan Valley under any peace deal.

"That is why Prime Minister Netanyahu expects to hear a reaffirmation from President Obama of U.S. commitments made to Israel in 2004," the statement added, alluding to a letter from former President George W. Bush saying a return to the 1967 lines would be "unrealistic."

"Those commitments also ensure Israel's well-being as a Jewish state by making clear that Palestinian refugees will settle in a future Palestinian state rather than in Israel," the statement noted.

Obama acknowledged that Israeli-Palestinian peace talks were made more difficult by the Palestinians' decision form a Fatah-Hamas unity government. That decision raises "profound and legitimate questions" for Israel, due to Hamas' refusal to recognize Israel's right to exist, and Palestinian leaders will have to come up with credible answers, he said.

Nevertheless, he added, he is convinced that most Israelis and Palestinians want peace, and therefore, negotiations must happen. He said the parties should "move forward" on the issues of territory and security now and leave Jerusalem and the refugees for later.

Obama also rejected the Palestinians' plan to seek UN recognition of a state in September. "For the Palestinians, efforts to delegitimize Israel will end in failure," he said. "Symbolic actions to isolate Israel at the United Nations in September won't create an independent state."

Chief Palestinian negotiator Saeb Erekat said afterward that Palestinian Authority President Mahmoud Abbas would call an emergency meeting of the Palestinian leadership and consult with other Arab leaders over this call for the Palestinians to end the conflict through negotiations rather than unilateral action. But he also said Abbas welcomed Obama's efforts to renew talks with Israel.

Netanyahu will meet with Obama at the White House today, and the two are expected to issue a joint statement after their talks. The trip is being billed as one of the prime minister's most important. It will also feature a speech to the pro-Israel lobby AIPAC and an appearance before a joint session of Congress.