UN Secretary-General Antonio Guterres on Tuesday called on Yemeni parties to agree on a joint declaration on a nationwide cease-fire, economic and humanitarian measures and the resumption of the political process.

"We need an immediate cease-fire and return to the negotiating table to work out a political settlement to end the war. Nothing less will suffice," he told the Security Council in a high-level debate on the Gulf region.

"I acknowledge the painstaking compromise being asked of the parties to finalize this set of agreements. I reiterate my call on them to continue their engagement with my envoy -- without preconditions -- to finalize the joint declaration."

Yemeni women and youth must also be part of the process to ensure an inclusive and sustainable solution, he said.

There is no doubt that tensions in the Gulf region have complicated efforts to find a peaceful settlement in Yemen. Yet the swift resolution of the Yemen conflict can contribute to building trust and confidence throughout the region, he said.

"The conflict is a reminder that unless we address the urgent and immediate regional challenges, instability could spread farther and wider."

Yemen has been in civil war since 2015, pitting Houthi militia against the forces loyal to the internationally recognized Yemeni government. The conflict also involves regional powers. A Saudi-led military coalition is striking Houthi rebels, which are allegedly supported by Iran.

Yemen remains the largest humanitarian emergency as nearly six years of war have devastated the lives of millions of Yemenis. Famine is looming, and it is all compounded further by the continued spread of COVID-19, said Guterres.

He applauded last week's "promising steps" by the parties to release more than 1,000 prisoners -- the largest prisoner exchange since the start of the conflict.

"This action not only reunited many Yemeni families with their loved ones, but also demonstrated that the parties are able to reach agreement and follow through on their commitments," he said.

But he warned that the security situation in Yemen remains fragile as evidenced by a further escalation of conflict over the recent weeks. Fortunately, for now, hostilities have subsided, he said.