The United Nations welcomes the first commercial flight scheduled out of the Sanaa, Yemen airport in six years as an essential step in a two-month truce, a UN spokesman said on Thursday.

The flight to Amman, Jordan, is scheduled to take off on Sunday, said Stephane Dujarric, the chief spokesman for UN Secretary-General Antonio Guterres. "The UN thanks the Hashemite Kingdom of Jordan for its support in bringing about this achievement, and the Government of Yemen for its constructive role in making this happen."

The world body counts on all parties involved to ensure a successful flight, Dujarric said. The flight is an important element of the truce between the government and the Houthi militia recently reached through the mediation efforts of Hans Grundberg, the UN special envoy for Yemen.

The spokesman expressed the hope that parties to the accord will continue facilitating the flights as terms of the truce agreement.

"Grundberg is working with the parties to ensure the successful implementation of the truce, including making progress towards opening roads in Taiz and other governorates to facilitate Yemenis' freedom of movement within their country," Dujarric said. Grundberg is also engaging the parties to strengthen and extend the truce and build on its momentum towards a sustainable political solution to the conflict.

Yemen has been mired in a civil war since late 2014, when the Houthi militia seized control of several northern provinces and forced the Saudi-backed Yemeni government out of the capital Sanaa.