PA Chairman Mahmoud Abbas
PA Chairman Mahmoud AbbasFlash 90

Palestinian Authority Chairman Mahmoud Abbas said on Tuesday that U.S. Secretary of State John Kerry had made "useful and constructive proposals" during his four-day visit last week and said he was "optimistic" about the outcome, reported the AFP news agency.

His remarks, at a news conference with visiting Italian Prime Minister Enrico Letta, came in the wake of Kerry's latest attempt to coax Israel and the PA back into direct peace talks.

"Kerry made useful and constructive proposals and we are not saying they were bad, but they need further clarification and explanation before we can return to negotiations," Abbas said, according to AFP.

"We are optimistic because Kerry is serious and determined to reach a solution. We hope to go back to negotiations very soon in order to address the core issues between us and the Israelis," he added.

Although Kerry flew out of the region on Sunday, he left behind several of his advisers and is expected to return to the region soon, Abbas said.

Amin Maqbul, a senior official in Abbas's ruling Fatah movement, said there had been "progress" during Kerry's marathon talks and expressed appreciation for his commitment to the establishment of a Palestinian state along the borders that existed before the Six Day War in 1967.

"He has made it clear that this is U.S. policy," he told Voice of Palestine radio, adding that there had also been progress on the issue of Israel's release of terrorist prisoners.

"Settlements remain the main obstacle to a resumption of negotiations," he said, calling for added U.S. pressure on the Israeli government on all issues.

Abbas has insisted that Israel recognize the 1949 Armistice Line as a designated border for any future PA state. Israel refuses, as the pre-1967 borders are indefensible and withdrawing back to these borders would guarantee its destruction.

The demand that Israel recognize these indefensible borders as a designated border for a Palestinian state is just one in a long line of preconditions that Abbas has imposed on negotiations. He has also demanded that Israel release terrorists jailed before the 1993 Oslo Accords and that it freeze all Jewish construction in Judea, Samaria and eastern Jerusalem.

Under U.S. pressure, Israel froze construction for ten months in 2010 so that Abbas would agree to resume negotiations. When the freeze ended, however, Abbas refused to talk, demanding instead that Israel continue to freeze construction.

Prime Minister Binyamin Netanyahu said on Monday that he is “ready to go into the tent, the peace tent, and stay in the tent until white smoke comes out.” He has consistently called on Abbas to resume talks without preconditions, but Abbas has ignored the calls, saying instead that “the ball is in Israel’s court.”

The optimism displayed by Abbas was not reflected on the ground, with a new Israel-PA survey showing most people held little hope the talks would result in a resumption of direct talks after a hiatus of nearly three years.

According to a poll jointly conducted by the Harry S. Truman Research Institute for the Advancement of Peace at Jerusalem's Hebrew University and the Palestinian Center for Policy and Survey Research in Ramallah, just over a quarter of PA Arabs -- 27 percent -- and only one in 10 Israelis, believe that talks will resume and violence will end, reported AFP.

Just over two thirds of both peoples -- 68 percent of Israelis and 69 percent of PA Arabs -- view the likelihood of a Palestinian state emerging in the next five years as low or non-existent.