Less than two weeks before the UN General Assembly is to meet, Palestinian Authority President Mahmoud Abbas remains adamant in his refusal to meet with Prime Minister Benjamin Netanyahu, potentially jeopardizing the Obama administration's plans to hold a tripartite meeting in New York on September 23 or 24.

Abbas insists there will be no meeting with Netanyahu, nor a resumption of negotiations, unless Israel completely freezes settlement construction in the West Bank and East Jerusalem.

The United States and Israel are still hoping that an agreement on a temporary freeze in settlement construction, along with an Israeli announcement to that effect, will convince Abbas to change his mind.

Haaretz has learned that Abbas has relayed messages in recent days to senior U.S. and European officials, as well as Israeli officials, saying he did not intend to participate in a tripartite meeting at the UN General Assembly and that he was not willing to meet with Netanyahu.

A political source in Jerusalem said that Israel's recent announcement of 455 new building permits and the delay in declaring a freeze in settlement construction are the reasons Abbas is refusing to participate in a tripartite meeting at the United Nations with U.S. President Barack Obama and Netanyahu.

During a meeting with Spanish Foreign Minister Miguel Moratinos on Wednesday, Netanyahu said he was uncertain that a tripartite meeting would be held in New York. He said that if a meeting with Abbas did not take place at the UN, then one was likely to take place in early October.

"We have wanted this meeting for five months now," Netanyahu asserted. "It is the Palestinians who are posing preconditions to a meeting."

Netanyahu also expressed a degree of disappointment at the extent of goodwill gestures from the Arab states the Obama administration had managed to receive in exchange for Israel's intention to freeze West Bank settlement construction. The prime minister told Moratinos that "it was a modest normalization package" and highlighted the refusal of Saudi Arabia to agree to make a goodwill gesture toward Israel.

Netanyahu said the U.S. administration continues to pressure the Arab states, and a certain amount of progress had been achieved in a number of Persian Gulf states.

For the Obama administration, a tripartite meeting at the UN has great significance as the United States would like to transform the event into the starting point for the resumption of negotiations between the two sides, and are thus presenting it as a substantial step forward.

The Palestinian stance is causing a great deal of agitation among American officials, who are concerned about the possibility of failing to arrange a meeting. The Americans have relayed messages to both Israel and the Palestinian Authority in recent days, urging the two sides to moderate their positions in order for a meeting to take place.

On Saturday night, U.S. envoy to the Middle East, George Mitchell, is due to arrive in Israel for meetings in Jerusalem and Ramallah, and is expected to pressure Abbas to meet with Netanyahu. Mitchell is also scheduled to travel to other countries in the region.

In Jerusalem, the U.S. envoy will seek to finalize a deal with Netanyahu on the hiatus in settlement construction. There is still disagreement between the United States and Israel on the duration of the freeze. The Spanish foreign minister told Netanyahu that Mitchell had told him the United States was demanding a year-long freeze. Netanyahu did not offer any details but said that the "matter had not yet been finalized."

The prime minister would like to see a six-month freeze go into effect, while analysts have said that a likely compromise will result in a nine-month freeze. The unresolved issue of settlement construction continues to add tension to U.S.-Israel relations. Rumors that Mitchell would cancel his trip to Israel had also circulated.

On Wednesday, State Department spokesman Ian Kelly said that as far as the United States is concerned, "Israel is obligated to cease settlement construction in East Jerusalem and the West Bank, or anywhere outside the borders of 1967." He also said that the efforts now are concentrating on creating the right atmosphere between Israel and the Palestinians so that they can sit and resolve the ongoing conflict.

Mitchell is scheduled to meet with Defense Minister Ehud Barak on Sunday and with Netanyahu on Monday. Sunday afternoon Netanyahu will travel to Cairo for a meeting with Egyptian President Hosni Mubarak. Netanyahu and Mubarak will discuss the developments on the issue of captive Israeli soldier Gilad Shalit, held by Hamas since 2006.

However, the crux of the conversation with Mubarak will be the resumption of negotiations between Israel and the Palestinians, and the Israeli leader will seek the president's assistance in convincing Abbas to attend a tripartite meeting in New York.