Mahmoud Abbas says U.S. agreed to 1948 cease-fire lines as talks' base 2 (UPI) -- Lead Palestinian and Israeli negotiators are to meet Tuesday for the next round of peace talks, an official of the Fatah Party said Monday. When making the announcement, Nabil Shaath offered no other details, Palestinian news agency Ma'an reported. No progress has been made since talks resumed last month, Shaath said, adding that the Palestinian Authority may reach out to international groups if negotiations don't progress. Israeli and Palestinian negotiators formally resumed direct peace talks after a nearly three-year lull, the result of shuttle diplomacy by U.S. Secretary of State John Kerry. In Ramallah, West Bank, Palestinian Authority President Mahmoud Abbas said Monday the United States promised him it would back the Palestinian Authority's demands that Israel withdraw to the 1948 cease-fire lines as the foundation for any final status agreement with Israel, Israeli broadcaster Arutz Sheva reported. Abbas' comments contradicted claims by Israeli officials that the Palestinian Authority agreed to Israel's retention of the so-called "settlement blocs." In his speech, Abbas said the United States made the pledge before negotiations began and that without it the Palestinian Authority wouldn't have agreed to resume negotiations. Israel has said that it did not agree to any preconditions to enter the talks. Prime Minister Binyamin Netanyahu also said final status agreement must include Israel's retention of the settlement blocs. Netanyahu said the recent release of about 100 Palestinian prisoners by Israel was meant to encourage Palestinian leaders to resume talks.