The Palestinians are negotiating statehood with Israel on the basis of the pre-1967 lines, and the talks are making headway, Palestinian Authority President Mahmoud Abbas told officials from his Fatah party, according to an Israel Radio report Monday.

Abbas said he agreed to July’s resumption of talks “only once he’d received an official US guarantee that negotiations would be on a two-state solution based on the pre-1967 lines,” the report said. Israel’s Prime Minister Benjamin Netanyahu had emphatically refused Abbas’s demand, ahead of the talks, to publicly state that negotiations for a Palestinian state would be based on the pre-’67 lines, and the United States has not made public any assurances it may have made on the issue to Abbas.

Abbas also reportedly told the Fatah officials that the Palestinians are maintaining their demand that East Jerusalem be the capital of a future Palestinian state, a condition he called a “red line.”

Israel’s President Shimon Peres said Monday that Netanyahu had decided that Israel’s interests require a two-state solution, hence his readiness to resume negotiations with Abbas. Netanyahu had taken a “difficult decision” to restart talks with the Palestinians, said Peres, “and I respect that. I don’t believe he took it as an isolated step. He decided upon two states and no less important he decided against a bi-national state.”

Mideast U.S. Secretary of State John Kerry, Israeli President Shimon Peres, left, and Palestinian President Mahmoud Abbas, right, participate in the World Economic Forum on the Middle East and North Africa at the King Hussein Convention Center at the Dead Sea in Jordan Sunday May 26, 2013

Mideast U.S. Secretary of State John Kerry, Israeli President Shimon Peres, left, and Palestinian President Mahmoud Abbas, right, participate in the World Economic Forum on the Middle East and North Africa at the King Hussein Convention Center at the Dead Sea in Jordan Sunday May 26, 2013

In their negotiations over the past month or so, Israel has presented its overall position on the core issues and the Palestinians are preparing a response, the report quoted Abbas as saying. The talks have reached a “review of positions,” he reportedly said, without elaboration.

Meetings between Israeli and Palestinian envoys have taken place “continuously since final status negotiations resumed on July 29,” US State Department spokeswoman Jen Psaki said Sunday in a written statement.

“The negotiations have been serious, and US Special Envoy Martin Indyk and his team have been fully briefed on the bilateral talks and also participated in a bilateral negotiating session,” Psaki added. “As we have said in the past, we are not planning to read out the details of these meetings.”

Israeli and Palestinian negotiators have been tight-lipped about the talks, refusing even to disclose when and where they are held.

According to the radio report, however, Abbas confirmed for the first time that Israel agreed to release 104 Palestinian prisoners on condition that the Palestinians don’t appeal to international organizations about statehood, and as a goodwill gesture to help restart negotiations.

The first 26 prisoners, almost all of whom were convicted of killing Israeli soldiers or civilians before the 1993 Olso peace accords, were released on August 14Abbas added that during coming negotiations the Palestinians will ask for the release of a further 250 prisoners.

Palestinian Authority Prime Minister Rami Hamdallah said on Sunday that Israel may be ready to release more Palestinian prisoners soon.

“It is possible that the second batch of pre-Oslo prisoners will be released before the end of this month,” Hamdallah said according to the Palestinian Ma’an news agency.