The Saudi-led military coalition fighting Yemen's Houthi rebels last week announced it had closed all air, land and seaports in Yemen to stem what it said was the flow of arms to the Houthis from Iran. "There are many sources of supply to Yemen, even during the past week or so".
The ports were closed after Houthis attacked Riyadh near its worldwide airport through a ballistic missile on November 4.
It says those ports are in Aden, Mocha and Mukalla.
The strike "led to the total destruction of the VOR/DME radio navigation system, taking it offline and thus halting the only flights at Sanaa airport - those of the United Nations and other global organisations delivering humanitarian assistance", the rebel-run General Authority for Civil Aviation said in a statement. The war has killed over 10,000 civilians, displaced 3 million people and left much of the country's infrastructure in ruins.
Jamie McGoldrick of the UN Office for the Co-ordination of Humanitarian Affairs, who is based in Amman, said UN staff had visited the airport and spoken with authorities there.
The announcement from the Saudi mission at the United Nations came after the coalition fighting Yemen's rebels, known as Houthis, faced widespread worldwide criticism over the closure, with the U.N. and over 20 aid groups saying it could bring millions of already suffering people closer to "starvation and death".
"The humanitarian impact of what is happening here right now is unimaginable", Mr. McGoldrick told reporters.
On Monday Saudi agreed to reopen ports in government controlled areas, but demanded extra security measures be put in place around the rebel controlled port of Hodeida.
While coalition announcements about the availability of two ports in southern Yemen are "helpful", the key need is access to the rebel-held Red Sea ports of Salif and Hodeida, which are now inaccessible to United Nations aid shipments.
Some 2,000 of those deaths were the result of a cholera epidemic that swept rebel-held areas this summer, with half a million people infected.
Aden, on the south coast of Aden, is the stronghold of the internationally recognised, Saudi-backed government of President Abdrabu Mansur Hadi.
Saudi Arabia and its allies intervened in neighbouring Yemen in March 2015 to push back the rebels who control the capital Sanaa, in an attempt to restore the Hadi government to power. On Tuesday, the United Nations called on Saudi Arabia to fully open the ports of Yemen to deliver humanitarian aid to the country.