JERUSALEM, Oct 26 (Reuters) - A senior aide to Palestinian President Mahmoud Abbas condemned Israel's plan to cut power supplies to the Hamas-run Gaza Strip shortly before Abbas was to meet Israeli Prime Minister Ehud Olmert on Friday. Saeb Erekat called on the international community to "intervene immediately to protect the Palestinian people and compel Israel to comply with international humanitarian law". On Thursday, Israeli Defence Minister Ehud Barak approved the reduction of power supplies to the Gaza Strip in response to Palestinian rocket attacks, but it was not immediately clear when the power cuts to the 1.5 million Palestinians will begin. Abbas and Olmert were due to meet over lunch in Jerusalem as they seek common ground before a U.S.-hosted conference in Annapolis aimed at agreeing how to found a Palestinian state." Those hopes of statehood suffered a setback when Abbas's Islamist opponents in Hamas seized control of Gaza in June. While profoundly hostile to Hamas, Abbas's secular Fatah faction and the Palestinian Authority it controls in the West Bank have spoken out against Israeli action in Gaza, where troops killed three militants in raids on Friday. Erekat, a senior peace negotiator with the Israelis, said the Israeli government's decision was a "provocation" that would "double the suffering" of those living in the coastal enclave. Speaking separately, Erekat said Abbas and Olmert would review the progress of negotiations at their meeting: "They will ... give their instructions on how to proceed to reach a joint document in preparation for the Annapolis meeting. "We are seriously discussing all the core issues."