Arab League chief Amr Moussa said on Sunday he had little hope that direct peace talks between Israel and the Palestinians, which are due to start on Thursday, will be successful.
He also said that he would not seek re-election as secretary general of the Arab League after his second mandate expires in March.
"We are hoping that talks will succeed but we are all very pessimistic about the viability of the peace process because of the past experience," Moussa told Reuters in an interview on the sidelines of a political conference in Slovenia.
He said U.S. President Barack Obama's sponsorship of talks was the only reason to hope for success.
"The only reason [for the hope in the success of the talks] is the sincerity of President Obama and his wish to achieve something good in his presidency," Moussa said.
He said Obama had given the Palestinians assurances that Israel would stop settling new territory during talks that are due to last for one year.
"If we find that during that year Israel continues to build settlements, there is no use in waiting for the full year [of talks]" Moussa said.
"Then we will have to reconsider the situation because you cannot negotiate while the Israelis are settling the territory," he added.
Asked whether he would run for another mandate as the Arab League chief, Moussa said: "It is not my intention to do so."
Meanwhile Sunday, Vice Premier Silvan Shalom said that Israel would not vote on extending the currently instated temporary freeze on Israeli construction in West Bank settlements before the start of the peace talks in Washington on September 2.
The 10-month freeze is set to expire on September 26. Palestinian officials have declared that talks would break down if Israel resumed construction in the settlements after that date.
Netanyahu, facing pressure from pro-settler groups in his own government, met other ministers on Sunday to discuss a compromise to permit construction to resume only in several settlement blocs Israel seeks to keep under any peace deal.
Shalom said in an interview that Prime Minister Benjamin Netanyahu promised him his cabinet would vote on the issue only after the Jewish High Holidays later this month, which fall after the peace summit is held.
"He told us today there will be no decision on Sept. 2 about freezing settlements," Shalom said, quoting Netanyahu from a closed door session with ministers earlier on Sunday, adding it would be at least two weeks before the government would vote.
Shalom, a veteran member of Netanyahu's right-wing Likud party, said he objected to the idea and rejected the Palestinian call for Israel to extend its settlement freeze ahead of talks was "an unacceptable demand".
He said any decision to ultimately extend the settlement freeze may also create a rift that could topple Netanyahu's coalition government and force an early national election.
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