Defense Minister Ehud Barak on Tuesday urged United Nations Secretary-General Ban Ki-moon to help push Palestinian Authority President Mahmoud Abbas to renew peace talks with Israel.

Ban expressed his concern to Barak over the humanitarian situation in the Gaza Strip and requested that Israel ease Palestinians' movement at Gaza border crossings. Barak said that Israel has been tending to Gazans' needs.

A top Palestinian Authority official said earlier Tuesday that he did not foresee a trilateral meet with Israel and Egypt in the near future, declaring that Israel was posing demands that made a resumption of peace talks impossible.

"Israel is insisting on the impossible," chief Palestinian negotiator Saeb Erekat told Army Radio. "It is [Israel] who is setting conditions. We demand an authorized Israeli leader publicly commit to negotiations based on the 1967 borders, in accordance with the road map plan."

"[Israel] is demanding that a unified Jerusalem be it's capital, is continuing construction in the eastern part of the city and wants to control 40 percent of the West Bank - and yet you say you have no preconditions," said Erekat. "As the situation looks now, I really don't see a possibility for a summit."

Click here for Haaretz.com Q & A with Saeb Erekat

Erekat's remarks came a day after Prime Minister Benjamin Netanyahu expressed cautious optimism that talks with the Palestinians would soon resume.

"In recent weeks, I've had the impression there is a certain change in atmosphere, and I hope that a maturation that would enable the negotiating process to move forward has occurred," he told a meeting of his Likud faction at the Knesset.

Officials in the Prime Minister's Office said Netanyahu was particularly encouraged by Monday's meeting between Abbas and Egyptian President Hosni Mubarak.

But Abbas on Tuesday shot down reports that new developments were afoot in the peace process with Israel. The Palestinian president told Al-Jazeera television that he has yet to see the details of an American peace plan nor has he become aware of American guarantees for the PA in the event that negotiations with Israel resume.

Abbas said that the Palestinians would wait to hear what U.S. President Barack Obama's special envoy to the region, George Mitchell, had to offer during his visit next week before publicly adopting a position on renewing talks. An unnamed Palestinian official told Al-Jazeera that Abbas met with Mitchell on Saturday in Amman.

Abbas also said that he would postpone any decision on whether or not to restart the talks until he sees what happens during next week's visit to Washington by two senior Egyptian officials, Foreign Minister Ahmed Aboul Gheit and intelligence chief Omar Suleiman.

Israeli officials have predicted that Abbas will first try to wrest as many guarantees as possible from the American administration.

For weeks, the Palestinian leader has been insisting that he will not resume negotiations unless Israel completely freezes construction in West Bank settlements and in East Jerusalem.