WASHINGTON (Reuters) – U.S. President Barack Obama's endorsement of a longstanding Palestinian demand on the borders of their future state sets the stage for what could be a tense meeting with Israeli Prime Minister Benjamin Netanyahu on Friday.

Netanyahu, who has had strained relations with Obama, headed for Washington saying the president's vision of a Palestinian state on the borders of 1967 -- as part of his vision for an elusive U.S.-brokered peace deal -- could leave Israel "indefensible."

The White House talks had never been expected to yield any significant progress to revive long-stalled peace talks, but now that prospect seemed dimmer than ever.

Obama, in a policy speech on Thursday on the "Arab spring" uprisings across the Middle East, laid down his clearest markers yet on the compromises Israel and the Palestinians must make for resolving their decades-old conflict.