SANAA — Yemen’s dominant Houthi group and its allies in ex-president Ali Abdullah Saleh’s party said on Thursday they would establish a governing council to run the country, in a move the United Nations said threatens peace talks in Kuwait.

Senior officials in President Abd-Rabbu Mansour Hadi’s government said the move undermined diplomatic efforts to end a devastating civil war that has drawn in a Saudi-led Arab coalition and caused a humanitarian crisis.

The announcement by the Iranian-allied Houthis and Saleh’s General Peoples’ Congress Party (GPC) could unravel an already shaky ceasefire that took effect in April and had reduced the intensity of the conflict.

U.N. Yemen envoy, Ismail Ould Cheikh Ahmed, said the move gravely violated U.N. Security Council Resolution 2216, which calls on the Houthis “to refrain from further unilateral actions that could undermine the political transition in Yemen.”

The talks under way in Kuwait had made little progress on U.N. peace proposals including a Houthi withdrawal from cities including the capital Sanaa captured since 2014 and the creation of an inclusive, more democratic government.

A statement carried by the Houthi-run sabanews.net news agency said the new council would entail a rotating leadership including a president and a deputy from each ally.

It said the deal was signed by GPC deputy head Sadeq Abu Ras and the Houthis’ Ansarullah political council chief, Saleh al-Samad, and outlined a basis for running the country and managing state affairs on the basis of the existing constitution.

Houthi forces and Saleh loyalists now hold most of Yemen’s northern half while Hadi’s forces share control of the rest with southern separatists and various tribes, with al Qaeda-affiliated militants operating in parts of the country.

The accord as quoted by the sabanews.net cited what it called the international community’s failure to rein in the “arrogance of the Saudi aggression” as an important factor in the decision to ditch the peace talks.