Palestinian Authority chief Mahmoud Abbas warned early Tuesday that Israel's settlement of occupied territories has become "a time bomb" that could destroy peace hopes at any moment. His comments came as U.N. Secretary General Ban Ki-moon said in a message to mark an international day for Palestinians that there was little sign of optimism by Palestinians or Israelis that a peace accord could be achieved soon. In a special message read at the U.N. headquarters, Abbas said "the deterioration in the peace process must be addressed." "This requires bringing a decisive and final end to the vicious Israeli settlement campaign," the Palestinian leader added. The settlement "constitutes a time bomb that could destroy everything we have accomplished on the road to peace at any moment," he stressed. On his part, Ban urged Israel to halt the settlement building which he called "a serious blow to the credibility of the political process." The Palestinian side, he added, "must continue to roll out the institutions of statehood, combat terrorist attacks and curb incitement."