UN Secretary General Ban Ki-moon is “alarmed” by Israeli plans to expropriate 988 acres of Palestinian land in the Bethlehem area in the south of the occupied West Bank, his spokesman said Monday.

Israel announced the move on Sunday, the army saying the step stemmed from political decisions taken after the June killing of three Israeli teenagers snatched from a roadside in the same area, known to Israelis as the Etzion settlement bloc.

“The Secretary-General is alarmed by yesterday’s announcement by Israeli authorities to declare as so-called ‘state land’ nearly 1,000 acres of land in the Bethlehem area of the West Bank,” the spokesman said.

“The seizure of such a large swathe of land risks paving the way for further settlement activity, which -– as the United Nations has reiterated on many occasions -– is illegal under international law and runs totally counter to the pursuit of a two-state solution.

“The secretary-general calls on Israel to heed the calls of the international community to refrain from settlement activity and abide by its commitments under international law and the Quartet Road Map.”

The United States urged Israel earlier Monday to reverse the plan, which has angered the Palestinians and alarmed Israeli peace campaigners.

Egypt — which last week mediated a ceasefire between Israel and the Hamas rulers of the Gaza Strip to end a 50-day war — also denounced Israel’s move.

“This is not a positive step — it contradicts international law and will have negative consequences on the peace process,” a foreign ministry statement in Cairo said. It added that the plan would be “an obstacle” to a two-state solution between Israel and the Palestinians.

Rights watchdog Amnesty International similarly denounced the Israeli plans, saying that it “appears to be the largest land grab in the occupied Palestinian territories since 1980.”

“Israel’s strategy of illegally confiscating land for settlements in the West Bank must stop once and for all,” said Amnesty’s Philip Luther.

The Palestinians have called for diplomatic action against Israel, while Israeli peace campaigners said the land expropriation is the biggest of its kind in three decades.

The US and UK have also heavily criticized the move, with Washington calling it “counterproductive” and Britain urging Jerusalem to reverse its “ill-judged decision.”

On Sunday, the IDF’s Civil Administration, the military government in the West Bank, announced that per instructions from Jerusalem “4,000 dunams at (the settlement of) Gvaot is declared as state land,” and said concerned parties had 45 days to appeal.

The Palestinian Authority decried Israel’s announcement on Sunday, with chief negotiator Saeb Erekat calling for diplomatic action.

“The Israeli government is committing various crimes against the Palestinian people and their occupied land,” he told AFP. “The international community should hold Israel accountable as soon as possible for its crimes and raids against our people in Gaza and the ongoing Israeli settlement activity in the West Bank and East Jerusalem.”

Coordinator of Government Activities in the Territories Major-General Yoav Mordechai said that the move comes “as the continuation of the political leadership’s directives given at the end of Operation Brother’s Keeper.”

The Israeli army declared that there was no claim of Palestinian ownership on the land in question, the Ynet news site reported.

The move was described as a response to the killing in June of three Israeli teenagers in the Etzion Bloc.

Israel accused Hamas of being behind the June 12 abduction and killing of Naftali Fraenkel, 16, Gil-ad Shaar, 16, and Eyal Yifrach, 19. The three were last seen at a hitchhiking post outside the settlement of Alon Shvut in Gush Etzion south of Jerusalem. The abduction sparked Operation Brother’s Keeper, a massive search to locate the teenagers and a crackdown on Hamas in the West Bank, with hundreds arrested. The bodies of the three teens were found near Hebron on June 30, and a number of Israeli hardliners set up unauthorized West Bank outposts in response.

The Etzion settlement council welcomed Sunday’s announcement, and said it was the prelude to expansion of the current Gvaot settlement.

It “paves the way for the new city of Gvaot,” a statement said.

“The goal of the murderers of those three youths was to sow fear among us, to disrupt our daily lives and to call into doubt our right to the land,” it said. “Our response is to strengthen settlement.”