The UN's special Mideast envoy called Wednesday on Israel to drop plans to annex parts of the occupied West Bank, joining a growing international chorus of opposition.
Envoy Nickolay Mladenov also called on the Palestinians to resume talks with the so-called Quartet, comprising the US, Russia, the EU and the United Nations.
"Israel must abandon threats of annexation," Mladenov said during a meeting of the Security Council.
"I call on my colleagues in the Middle East Quartet to work with the UN and quickly come forward with a proposal that will enable the Quartet to take up its mediation role and work jointly with countries in the region to advance the prospect of peace," he added.
The unusually direct statement came a day after Palestinian president Mahmoud Abbas announced an end to the Palestinians' security arrangements with Israel, which plans to annex territories in the occupied West Bank.
Mladenov said he would speak Thursday with Palestinian leaders about the practical consequences of their announcement, which were not spelled out by Abbas.
"The continuing threat of annexation by Israel of parts of the West Bank would constitute a most serious violation of international law," Mladenov warned.
It would "deal a devastating blow to the two-state solution, close the door to a renewal of negotiations, and threaten efforts to advance regional peace and our broader efforts to maintain international peace and security," he added.
The US ambassador to the United Nations, Kelly Craft, stressed for her part that a solution could only result from the two parties sitting down at the same negotiating table.
"What is needed right now, if we hope to take even a first step in the right direction, is for the parties to sit down with one another," she said.
"This council cannot dictate the end of this conflict. We can only encourage the parties to sit down to determine how they wish to make progress."
The US diplomat once again called on the Palestinians to seize the opportunity offered by a US peace plan that it has previously rejected.
Several Security Council members such as Indonesia and the European countries have warned Israel against the planned annexations.
In a joint statement France, Belgium, Germany and Estonia reaffirmed that they "will not recognize any changes to the 1967 borders, unless agreed by Israelis and Palestinians."
"We strongly urge Israel to refrain from any unilateral decision that would lead to the annexation of any occupied Palestinian territory and would be, as such, contrary to international law," they said, reaffirming their support for a two state solution as the only one capable of bringing peace to the region.