The chief Palestinian negotiator on Tuesday played down expectations for President Barack Obama's latest attempt to restart peace talks, saying key differences with Israel make it difficult for negotiations to resume. The negotiator, Saeb Erekat, spoke ahead of talks in Washington this week with Obama's Mideast envoy, George Mitchell. The former US senator is holding separate meetings with Israeli and Palestinians teams in hopes of reviving the long-stalled peace talks. Erekat reiterated the Palestinians' insistence that Israel stop all settlement construction in the West Bank, and stressed there would be no direct talks with the Israelis during this week's trip to Washington. "There will not be Palestinian-Israeli negotiations in Washington," Erekat said. "There will be parallel American-Israeli negotiations and Palestinian-American negotiations." The talks in Washington are meant to follow up on Obama's summit last week with Prime Minister Binyamin Netanyahu and Palestinian Authority President Mahmoud Abbas in New York. Obama urged the sides to move beyond the two main sticking points - continued Israeli settlement construction and the framework for resuming talks. Israel has agreed to slow building in the West Bank, captured by Israel during the Six-Day War, but has rejected a total halt to construction. Israel pledged to stop settlement building in a 2003 US-backed peace plan but has not done so, saying that the Palestinians have not carried out their obligations. The Palestinians also want negotiations to begin where they left off under Netanyahu's more dovish predecessor, Ehud Olmert. Netanyahu says he is not obligated to any concessions that Olmert made. After initially backing the Palestinian calls for an Israeli settlement freeze, the White House appears to have softened its position, saying it is time for the sides to start talking again even if settlement work continues. On Saturday, Secretary of State Hillary Rodham Clinton urged Arab nations to take steps toward normalizing relations with Israel in order to help get both sides to the negotiating table. Arab states reacted coolly to Clinton's suggestion. Representatives of Netanyahu and Defense Minister Ehud Barak are scheduled to meet with Mitchell on Wednesday. Erekat will hold separate talks with Mitchell later in the week. Among the many obstacles to a final peace deal is the Islamic group Hamas' control of the Gaza Strip. Hamas seized power there two years ago after routing forces loyal to Abbas' Fatah movement. Abbas rules only the West Bank. Israel, which considers Hamas a terrorist group, has said a final peace deal is impossible as long as the Palestinians are divided between two governments. On Monday, Hamas' exiled leader, Khaled Mashaal, said his group has agreed in principle to a proposal for reconciling with its Fatah rivals in a deal that would clear the way for new presidential and parliamentary elections. A final deal being brokered by Egyptian mediators will be drawn up and signed in October, Mashaal said in Cairo after talks with Egypt's intelligence chief. Erekat welcomed the news. "We hope the elections can take place," he said, adding that Palestinian politics must be conducted "in accordance with our national interest."