The Arab League held an emergency session on Tuesday evening after the Israeli prime minister announced the plan in a live press conference.
Netanyahu, who is fighting for his political life before elections on 17 September, said he would permanently seize up to a third of the West Bank, a move that for decades has been considered an endgame scenario for Palestinians’ aspirations of statehood.
“We haven’t had this kind of opportunity since the  six-day war, and may not have it again for another 50 years,” Netanyahu said, referring to the war in which Israel captured the land.
Arab foreign ministers meeting in Cairo condemned the plan as “a dangerous development and a new Israeli aggression by declaring the intention to violate the international law”.
“The league regards these statements as undermining the chances of any progress in the peace process and will torpedo all its foundations,” the ministers said.
Jordan’s foreign minister, Ayman Safadi, said Netanyahu’s plan was an outrageous election ploy and a “dangerous escalation that shatters the foundations of the peace process”.
Netanyahu made the announcement in front of a large map showing Israeli sovereignty extending over the vast majority of the Jordan Valley and slicing off the eastern border with Jordan.
“Killing all chances for peace for electoral purposes is irresponsible, dangerous,” Safadi added in a tweet.
Turkey’s foreign minister said the plan was racist and incendiary. “The election promise of Netanyahu, who is giving all kind of illegal, unlawful and aggressive messages before the election, is a racist apartheid state,” Mevlüt Çavuşoğlu wrote on Twitter.
“Will defend rights and interests of our Palestinian brothers & sisters till the end,” he added.
The president of the Palestinian Authority, Mahmoud Abbas, said he would pull out of any previous agreements signed with the Israeli government if it went ahead with the move – a threat he has previously made without following through.
“[We maintain] the right to defend our rights and achieve our goals through all available means regardless of the consequences,” Abbas said, according to a report by the state-run Wafa news agency.
Ayman Odeh, the leader of an alliance of Arab parties in Israel, called Netanyahu’s statement “not just election spin” but “a vision of apartheid”.
Netanyahu hinted on Tuesday night that the plan had the support of the White House. “I am waiting to do this in maximum coordination Trump,” he said in a speech broadcast live on Israeli television.