Although details of the agreement between the two factions remain to be worked out before a final signature, the prospect of internal Palestinian reconciliation appears certain to complicate efforts to broker a peace accord between Israel and the Palestinians.

Even before the understanding was formally announced, Israeli Prime Minister Binyamin Netanyahu put Palestinian Authority President Mahmoud Abbas on notice that reconciliation with Hamas would doom the peace process.

“The Palestinian Authority must choose between peace with Israel or peace with Hamas,” Netanyahu said in televised remarks. “Peace with both of them is impossible, because Hamas aspires to destroy the state of Israel and says so openly. It fires missiles on our cities. It fires antitank missiles at our children.” Netanyahu was referring to a recent attack on a school bus by militants in Gaza that killed a 16-year-old boy.