Prime Minister Benjamin Netanyahu said on Thursday Israel would object to any withdrawal to "indefensible" borders, adding he expected Washington to allow it to keep major settlement blocs in any peace deal.

In a statement after President Barack Obama's speech outlining Middle East strategy, Netanyahu said before heading to Washington that "the viability of a Palestinian state cannot come at the expense of Israel's existence".

"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 previous letter from Washington suggesting Israel could keep larger settlement blocs as part a peace deal with the Palestinians.

"Israel appreciates President's Obama commitment to peace," Netanyahu said, but stressed that he expects Obama to refrain from demanding that Israel withdraw to "indefensible" 1967 borders "which will leave a large population of Israelis in Judea and Samaria and outside Israel's borders."

The tough stand could set the stage for a tense meeting Friday when Netanyahu goes to the White House.

In his speech, Obama said a future Palestinian state must be based in territories captured by Israel in the 1967 Mideast war, with minor adjustments reached through negotiations.