President Mahmoud Abbas of the Palestinian Authority immediately denounced the plan as a “conspiracy deal” unworthy of serious consideration, making the decades-long pursuit of a so-called two-state solution appear more distant than ever. “We say a thousand times over: no, no, no,” Mr. Abbas said on Tuesday in Ramallah, in the West Bank.

As part of the proposal, Israel agreed to limit its settlement construction in a four-year “land freeze,” during which Palestinian leaders can reconsider whether to engage in talks.

But before returning to Israel on Tuesday, Mr. Netanyahu told reporters that he would ask his cabinet to vote Sunday on a unilateral annexation of the strategically important Jordan River Valley and all Jewish settlements in the West Bank, a move that is sure to further inflame the Palestinians.

Nearly three years in the making, Mr. Trump’s plan is the latest of numerous American efforts to settle the seemingly intractable conflict between Israel and the Palestinians. But it was a sharp turn in the American approach, dropping decades of support for only modest adjustments to Israeli borders drawn before 1967 and discarding the longtime goal of granting the Palestinians a wholly autonomous state.

The reaction of key Arab governments to the plan was mixed. In a statement, Jordan’s foreign minister affirmed his country’s support for an independent Palestinian state based on pre-1967 borders with East Jerusalem as its capital and warned against “the dangerous consequences of unilateral Israeli measures, such as annexation of Palestinian lands.”