RAMALLAH, West Bank, Aug 2 (Reuters/Mohammed Assadi) - The Palestinian president told a visiting US official on Monday that Israel must commit to clear terms of reference for peace talks before the start of direct negotiations, Palestinian officials said.

US President Barack Obama's administration is putting pressure on Palestinian President Mahmoud Abbas to agree to direct talks which Israeli Prime Minister Benjamin Netanyahu has said he is ready to begin immediately.

US official David Hale, a deputy to Obama's Middle East envoy George Mitchell, had asked Abbas when direct talks could begin, said members of the Palestine Liberation Organisation's (PLO) executive committee briefed by Abbas.

Mitchell has conducted five rounds of indirect talks between Abbas and Netanyahu since May. Obama has said he wants direct talks to begin by September.

The president answered Hale that we, in principle are not against direct negotiations, Saleh Rafat, an executive committee members said. However we should hear from the Israelis the terms of reference for the negotiations and a halt to settlement activities, he said. Netanyahu has said the Palestinians can bring all issues to the table and accuses Abbas of wasting time.

The Palestinians aim to found their state in the West Bank and the Gaza Strip with East Jerusalem as its capital. Israel occupied the territories in a 1967 war.

Abbas has sought progress in the indirect negotiations before any move to direct talks. He has spoken of unprecedented international pressure to convince him to resume direct peace talks with Israel.

Last week, the Arab League's peace process committee approved a move to direct negotiations when Abbas sees fit.

The PLO executive committee said in a statement after its meeting that the Palestinian demands were a guarantee for the success of future direct negotiations.

Without them, these talks will be sterile and destined to fail before they start, PLO spokesman Yasser Abed Rabbo said after the meeting.