Israeli prime minister Benjamin Netanyahu vowed on Tuesday to annex the heart of the West Bank if he wins re-election next week, a move that could inflame the Middle East and extinguish any remaining Palestinian hope of establishing a separate state.

Arab leaders angrily condemned Mr Netanyahu’s remarks, and a UN spokesman warned the step would be “devastating” to the prospects for a two-state solution.

Mr Netanyahu said he would extend Israeli sovereignty over the Jordan Valley, an area seen as the breadbasket of any Palestinian state, shortly after forming a new government, and would move later to annex other Jewish settlements.

Benjamin Netanyahu
Benjamin Netanyahu speaks during a press conference in Tel Aviv (Oded Balilty/AP)

Such action would swallow up most of the West Bank territory sought by the Palestinians, leaving them with little more than isolated enclaves.

Mr Netanyahu said it was important to act as US President Donald Trump prepares to unveil his Mideast peace plan after the September 17 election.

“This is a historic opportunity, a one-time opportunity, to extend Israeli sovereignty on our settlements in Judea and Samaria, and also on other important regions for our security, for our heritage, and for our future,” Mr Netanyahu said, using the biblical terms for the West Bank.

The prime minister was not clear about the status of the Palestinians on the West Bank.

More than 2.5 million Palestinians live there and in east Jerusalem, in addition to nearly 700,000 Jewish settlers.

Israel already has annexed east Jerusalem in a move that is not internationally recognised.

Mr Netanyahu is locked in a tight race, and his announcement, the most detailed vision for the region that he has presented during his decade in power, was the latest in a series of frenetic moves he has made in recent days to try to rally hard-line voters.

The proposal was dismissed by opponents as election theatrics, who have accused him of trying to divert attention from a corruption scandal and Israel’s security challenges.

Later in the day, he was whisked away from a campaign event in southern Israel after Palestinian militants fired rockets toward the area.

Mr Netanyahu’s plan would hinge on a number of factors, most critically whether Mr Trump would support him.

But major policy pronouncements are typically co-ordinated with the White House ahead of time, and a muted White House reaction indicated there would be little resistance.

US officials said Mr Netanyahu had told them about his proposal ahead of time and that they had not raised any objections because they do not think it will affect prospects for an eventual peace agreement.

Mr Netanyahu gave no indication of whether he had discussed his plans with Mr Trump but said he would wait for Mr Trump to unveil his peace plan and co-ordinate all steps with the president, whose team of Mideast advisers is dominated by supporters of the settlements.

The Palestinians seek the West Bank, east Jerusalem and the Gaza Strip, areas captured by Israel in the 1967 Mideast war, as part of a future independent state.

For Israel, the Jordan Valley is considered a security asset because it provides a buffer zone against potential attacks from the east.

Many moderate Israelis believe Israel should retain some element of control in the area under a peace deal.

Palestinians, however, say there can be no independent state without the area, which comprises nearly a quarter of the West Bank.

It is home to many Palestinian farms and also is one of the few remaining areas of the territory where the Palestinians have open space to develop.

Palestinian president Mahmoud Abbas said all agreements with Israel will be cancelled if Mr Netanyahu presses forward.

“We have the right to defend our rights and achieve our goals by all available means, whatever the results, as Mr Netanyahu’s decisions contradict the resolutions of international legitimacy and international law,” he said.

The international community, along with the Palestinians, overwhelmingly considers Israeli settlements in the West Bank and east Jerusalem illegal.

Mr Netanyahu’s plan would turn Palestinian population centres into enclaves that he said he would seek to link to neighbouring Jordan.

Unlike Israeli settlers, West Bank Palestinians are not Israeli citizens and do not have the right to vote.

Jordan’s foreign minister, Ayman Safadi, condemned the announcement as “a serious escalation that undermines all peace efforts”.

At the United Nations, secretary-general Antonio Guterres also rejected the proposal.

“Such a prospect would be devastating to the potential of reviving negotiations, regional peace and the very essence of a two-state solution,” said UN spokesman Stephane Dujarric.