The UN political chief is warning that chances of peacefully ending the Israeli-Palestinian conflict may be "irreparably damaged" unless steps are taken to prevent new Israeli settlement building and other "negative developments."

Jeffrey Feltman told the Security Council on Tuesday that four months since the resumption of Israeli-Palestinian talks aimed at a two-state solution, negotiators "have gone some way towards narrowing their differences."

But he said "strains have been growing dangerously between the parties."

Feltman cited "a significant setback" following a series of Israeli announcements of settlement plans in the West Bank, including East Jerusalem, especially the Nov. 13 announcement of 24,000 new units.

In protest at these developments, Feltman said Palestinian negotiators have submitted their resignations which are now under consideration by President Mahmoud Abbas.