Abbas made his statement in response to Prime Minister Benjamin Netanyahu's announcement that he will extend Israeli sovereignty to the two West Bank areas if he's re-elected in the upcoming election.
He called on the worldwide community to "act now to prevent Netanyahu and his allies from burying any remaining prospects for peace".
The United Nations said such a move would have no "international legal impact", while Turkey condemned it as "racist".
Such action would gobble up most of the West Bank territory sought by the Palestinians, leaving them with little more than isolated enclaves.
Netanyahu, who is fighting for his political life in a closely-contested election, reaffirmed a pledge to annex all Jewish settlements throughout the West Bank, but said such a move would not be made before publication of a long-awaited US peace plan and consultations with President Donald Trump.
Many in the worldwide community strongly condemned his announcement, suggesting it would kill any hope for the eventual emergence of a Palestinian state.
Netanyahu billed Tuesday's announcement as "dramatic", but it was essentially a repetition of promises he has made since April, when Israelis went to the polls in the first round election.
Netanyahu gave no indication of whether he had discussed his plans with Trump but said he would wait for 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.
Jordan's Foreign Minister Ayman Safadi warned the move risks "killing off the entire peace process".
The worldwide community, along with the Palestinians, overwhelmingly considers Israeli settlements in the West Bank and east Jerusalem illegal.
Senior Palestinian official Hanan Ashrawi said: 'He is not only destroying the two-state solution, he is destroying all chances of peace'.
The Jordan Valley accounts for around one-third of the West Bank and Israeli right-wing politicians have long viewed the strategic area as a part of the territory they would never retreat from.
The White House, for its part, did not issue a warning, nor did it say that Netanyahu's pledges would change American policy.
The premier, who used a map of the Jordan Valley to illustrate his plans, said Trump's peace parameters "will place before us a great challenge and also a great opportunity".
"I want to receive a clear mandate from you to apply Israeli sovereignty over all settlements".
Benjamin Netanyahu said he would annex the Jordan Valley, an area seen as the breadbasket of any Palestinian state, shortly after forming a new government and move later to annex remaining Jewish settlements.
Ahead of April elections, Trump recognised Israeli sovereignty over the occupied Golan Heights, seized from Syria in the 1967 Six-Day War.
The September election had to be called after Netanyahu failed to form a coalition.
Blue and White, led by former armed forces chief Benny Gantz, and Likud are running neck and neck in opinion polls.