US Mideast envoy George Mitchell arrived in Israel Monday evening for two days of talks with Israel and Palestinian leaders, even as Palestinian Authority President Mahmoud Abbas was coming under increased pressure from Palestinians to avoid direct talks with Israel.Mitchell, whose arrival was not announced until nearly the last minute, is scheduled to meet Prime Minister Binyamin Netanyahu on Tuesday. He is then expected to meet Abbas afterward, and leave the region on Wednesday.Both Israeli and US diplomatic officials have been saying for days that Mitchell was delaying his visit until there was something to talk about. His arrival Monday night however was not being interpreted by those same officials as an indication that Abbas has finally decided to agree to the launching of direct talks."I don't feel comfortable" saying that his arrival indicates a breakthrough, one Israeli official said. "It might be possible that they will get something out of Abbas, but I wouldn't hold your breath."Abbas has come under a great deal of pressure from the US, as well as Arab countries such as Egypt, Jordan and now even Saudi Arabia, to renew direct talks -- but so far has not budged.Diplomatic sources said that if the circumstances warranted it, Mitchell could – during his visit here – travel to Egypt and Saudi Arabia to discuss the matter.Meanwhile, representatives of dozens of Palestinian factions and organizations on Monday warned Abbas against succumbing to pressure to direct talks with Israel unconditionally.They claimed that Israel was planning to exploit the negotiations "to cover up for its practices, including the Judaisation of Jerusalem, continued settlement construction and the completion of the racist separation fence."They also warned that entering into direct talks with Israel under the conditions set by the US Administration would "save Israel from the international campaign of boycott and condemnation."In a statement issued in the West Bank, the representatives, who also included Fatah members, said: "We refuse to enter direct talks without agreement on the terms of reference, a timetable and a mechanism for implementing [an agreement]. We also demand an active international role and US assurances, as well as an Israeli commitment to abide by international law and United Nations resolutions."Qais Abdel Karim, a senior official with the Democratic Front for the Liberation of Palestine, said that entering direct talks without agreement on the terms of reference and a settlement freeze would be regarded as surrender to Israeli conditions.Abbas was quoted on Monday as saying that the Palestinians want to know the borders of their future state before entering direct talks with Israel.The Palestinians want Israel to recognize the 1967 lines as the borders of a Palestinian state as a precondition for entering into direct talks. They are also seeking US assurances that Israel would halt construction in all settlements, including Jewish neighborhoods in east Jerusalem.Abbas reiterated his readiness to launch direct negotiations with Israel once there's agreement on the terms of reference and the basis of the talks. "We want to know the borders where we're going to build our state," he said.Netanyahu, however, has said he would not agree to pre-conditions to negotiations that would, in effect, determine their outcome even before they start. He has also ruled out a continuation of the settlement freeze as a way to lure Abbas back to the table.