Israel's government hosted a celebration of 50 years of Jewish settlement Wednesday in the occupied West Bank and Golan Heights, angering the Palestinians and triggering a row with the supreme court.
Prime Minister Benjamin Netanyahu's right-wing government considers the commemoration a state occasion, with the premier expected to attend an evening ceremony in the West Bank.
Supreme court president Miriam Naor said that an official invitation to send a representative contained the wording "to celebrate the jubilee of the liberation of Judea, Samaria, the Jordan Valley and the Golan Heights".
On her instructions, the court declined the invitation.
The biblical term Judea and Samaria is used by the Israeli government to refer to the West Bank, of which the Jordan Valley is also part.
The territories were occupied by the Israeli army in the 1967 Six-Day War, along with Syria's Golan Heights, which were later annexed in a move never recognized by the international community.
Wednesday evening's gala event is to take place in the Gush Etzion settlement bloc, where the leftist Israeli government at the time encouraged the establishment of the first settlement in the occupied West Bank in September 1967.
Gush Etzion has now grown into a large bloc of settlements located outside Jerusalem, and officials expect it will be part of Israel under any future peace deal with the Palestinians.
"The settler celebrations on our occupied lands are unacceptable and make the atmosphere very tense," Palestinian presidential spokesman Nabil Abu Rudeina told AFP.
"We ask the American administration to urgently intervene to stop these provocations."
The event is to be attended by settler leaders, Netanyahu and ministers from his coalition government, seen as the most right-wing in Israel's history.
Leftist and centrist politicians have said they will not attend the event, which Labor MP Eitan Cabel wrote on Facebook is "totally meant to glorify Bibi and his group of extremists who lead us to the abyss," using Netanyahu's nickname.
Chief Justice Naor's decision to keep the court away from the event drew outrage from the right.
But she was quoted in a court statement as saying that she was acting in accordance with established procedure and not taking a stance.
"The president reached the conclusion that the event deals with an issue that is the subject of public controversy," it said.
"Therefore, without the president or justices of the supreme court taking a position on the controversy itself, the president decided that it would be appropriate for the judiciary not to participate in the event."
About 430,000 Israeli settlers live in the West Bank among 2.6 million Palestinians.
The settlements are illegal under international law and seen by a large part of the international community as a main obstacle to peace between Israelis and Palestinians.