The Palestinian Authority has condemned Prime Minister Benjamin Netanyahu for laying Israel's claim to certain West Bank land during a tree planting ceremony in a settlement bloc earlier Sunday, saying the move undermined efforts to return to the negotiating table.

"This is an unacceptable act that destroys all the efforts being exerted by Senator [George] Mitchell in order to bring the parties back to the negotiating table," Palestinian President Mahmoud Abbas' aide Nabil Abu Rudeineh said, referring to U.S. President Barack Obama's special Middle East envoy.

Contacts with the Americans would continue, Rudeineh said, but a return to negotiations with Israel appeared unlikely anytime soon.

Netanyahu pledged on Sunday that Israel would keep parts of the West Bank forever, planting trees in a settlement bloc to reaffirm a land claim long rooted in Israeli government policy.

"Our message is clear: We are planting here, we will stay here, we will build here, this place will be an inseparable part of the State of Israel for eternity," Netanyahu said in the Gush Etzion enclave.

Speaking after meeting Mitchell in Jerusalem, Netanyahu vowed Israel would also keep its two biggest West Bank settlements, Maale Adumim and Ariel.

His comments came as no surprise to the Palestinians, who were put on notice by previous Israeli leaders that Israel intended to hang on to major settlement blocs in the West Bank in any future peace accord.

Criticized by settler leaders for ordering in November - under U.S. pressure - a slowdown in constructing settlements, Netanyahu visited the West Bank to plant trees marking Israel's arbor day.

He made the symbolic visit just hours after meeting Mitchell, who has been trying to revive talks on Palestinian statehood suspended for the past 13 months.

"Today I heard some interesting ideas for renewing the [peace] process," Netanyahu said at the weekly meeting of his cabinet, without elaborating.

"I also expressed my hope that these new ideas will allow for the renewal of the process. Certainly if the Palestinians express a similar readiness, then we will find ourselves in a diplomatic process," Netanyahu said.

Mitchell told Palestinian leaders on Friday they must resume talks with Israel if they want U.S. help to achieve a peace treaty that creates a Palestinian state in the West Bank and Gaza Strip.

The Palestinians refuse to talk with Israel until it stops all settlement construction in the West Bank and East Jerusalem, areas it captured in the 1967 Six-Day War.

Palestinian President Mahmoud Abbas repeated that demand in talks later on Sunday with Mitchell in Amman, a spokesman for Abbas said.

"It's premature to talk about a real breakthrough," said the spokesman, Nabil Abu Rdainah. "President Abbas reassured [Mitchell] about his commitment to peace."

Mitchell also gave no sign that any progress had been made, telling told reporters in the Jordanian capital he had a "productive meeting" with Abbas on a full range of issues, and that he looked forward to continuing their discussions.

Netanyahu has said the housing-start freeze he ordered in West Bank settlements, other than those around Jerusalem, for 10 months was aimed at reviving peace negotiations.

Despite U.S. pressure, Abbas has not relented on settlements, citing a 2003 peace "road map" obliging Israel to freeze "all settlement activity" and the Palestinian Authority to begin "dismantlement of terrorist capabilities and infrastructure".

The World Court has ruled that Israeli settlements in the West Bank and East Jerusalem are illegal. Many Jewish settlers claim a God-given right to the West Bank, which they call by the biblical names Judea and Samaria