Palestinian Authority President Mahmoud Abbas speaks during a meeting of the Fatah Revolutionary Council in the West Bank city of Ramallah on July 20, 2010. (Majdi Mohammed/Associated Press))

Palestinian President Mahmoud Abbas told his Fatah movement he wants a more specific U.S. commitment on the borders of a future Palestinian state before agreeing to direct talks with Israel, an adviser said Wednesday.

Abbas told Fatah leaders in a closed-door meeting late Tuesday that President Barack Obama's assurances so far aren't clear enough.

Obama has urged Abbas to resume direct talks that broke off in December 2008.

However, Abbas first wants guarantees that a state will be established in the West Bank, Gaza and east Jerusalem, allowing for minor border adjustments. Israel captured those territories in the 1967 Mideast War.

"We expect huge pressure and hard days, but we will not go to negotiations like blind people and we will resist that [the pressure] peacefully," Abbas was quoted as telling Fatah leaders.

Abbas's comments were published Wednesday in a Palestinian daily, and confirmed by Abbas adviser Sabri Saidam, who was present at the meeting.

The Palestinian leader said Obama's assurances concerning the negotiations were delivered last week by U.S. Mideast envoy George Mitchell. Abbas was quoted as saying the U.S. president was less specific in defining what constitutes occupied Palestinian territory than the previous U.S. administration.

Israeli Prime Minister Benjamin Netanyahu says he wants to move to direct talks immediately, but refuses to agree to a framework for the negotiations. Palestinians are reluctant to engage with Netanyahu, who has retreated from some of the positions of his predecessors.

New report on Gaza offensive

In a separate development, the Israeli military has submitted a new report to the United Nations on its three-week offensive in Gaza in the winter of 2008-09.

It said it would take greater precautions to avoid civilian casualties, but reiterated that it considered the offensive a necessary and proportionate response to years of Hamas rocket attacks on Israeli towns.

Some 1,400 Gazans were killed in the war, including hundreds of civilians. Thirteen Israelis were also killed.

U.N. investigators wrote in a report last year that they found evidence that both sides committed war crimes. Hamas was cited for indiscriminate rocket fire on Israeli civilians, while Israel was accused of using disproportionate force and intentionally harming civilians.