TEHRAN (Press Shia Agency) – The Saudi-led coalition is still blocking desperately-needed UN aid deliveries to Yemen despite the re-opening of the port of Aden and of a land border crossing, a UN spokesman said.

"Humanitarian movements into Yemen remain blocked," Russell Geekie — a spokesman for the UN office of humanitarian aid OCHA — said Friday, AFP reported.

"The reopening of the port in Aden is not enough. We need to see the blockade of all the ports lifted, especially Hodeida, for both humanitarians and for commercial imports."

The coalition shut down Yemen's borders on Monday in response to a missile attack by Yemen near the Riyadh airport.

UN aid Chief Mark Lowcock told the Security Council this week that unless the blockade is lifted, Yemen will face "the largest famine the world has seen for many decades, with millions of victims".

After an outcry from the United Nations, the coalition on Wednesday reopened Aden, which is controlled by pro-Saudi forces, and on Thursday opened the land crossing at Wadea on the Saudi-Yemen border.

But Geekie said no aid had gone into Aden yet and the reopening of the Wadea crossing did not impact UN operations.

The port at Hodeida, which is held by Houthi movement, is key to UN aid efforts as it is closest to the majority of people in need.

The coalition accuses Houthis of using aid shipments to smuggle in weapons.

Before the blockade, UN aid agencies were delivering food and medicine through Hodeida, Saleef, and Aden ports.

"There can be no alternative for all these ports being fully functional and receiving commercial and humanitarian cargo," the spokesman said.

The United Nations has listed Yemen as the world's number one humanitarian crisis, with 17 million people in need of food, seven million of whom are at risk of famine.

More than 2,000 Yemenis have died in a cholera outbreak now affecting nearly one million people.