NEW YORK — The Iran-backed Houthi militia's closure of Sanaa Airport to aid is "very worrying," warned the United Nations Special Envoy to Yemen Martin Griffiths as he briefed the UN Security Council session on the latest developments in the war-torn country on Tuesday. Expressing his concerns over worsening situations in the central Yemeni province of Marib, the UN special envoy said: "The situation in Marib is of concern. Military shifts in Marib have ripple effects on conflict dynamics. If Marib falls, it'd undermine prospects of convening an inclusive political process that brings about a transition based on partnership and plurality." Griffiths said that the flow of essential commercial imports, including food, fuel, and medical supplies and their distribution throughout Yemen to civilians is of the highest priority. I'm concerned about the closure of Sanaa airport to humanitarian flights. He added: "Earlier this year, I warned that Yemen was at a critical juncture. I said either the guns would be silenced the political process would resume, or Yemen would slip back away from the road to peace. Alas, this is exactly what seems to be happening." The UN special envoy added: "Last week I sent the two parties an advanced draft of the Joint Declaration which reflects and balances their comments and incorporates inputs from civil society and women. My appeal is simple. Choose peace. End this conflict. Work with us urgently on the Joint Declaration." Reiterating his call for a ceasefire, Griffiths told the UNSC: "We expect to see the parties meet this week in Switzerland to continue discussing the implementation of prisoner exchanges under the joint auspices of my Office and International Committee of the Red Cross. I hope the meeting results in the release of these prisoners given the COVID-19 threat." Highlighting the role of the society in the resolution of the conflict, Griffiths told the UNSC: "Civil society role is central in maintaining the pressure for a peaceful resolution. My Office is engaging Yemeni civil society regarding the Joint Declaration negotiations is discussing plans to ensure their meaningful inclusion in a future political process." "Although the situation is very dire, the parties can choose to continue down the trajectory of escalating violence; or they can choose to make the compromises necessary to revive the political process and allow for a political settlement," the UN special envoy hoped.