Yemen also faces a deadly cholera outbreak and stands at the brink of starvation.
"And in Yemen, we particularly call on all sides to permit humanitarian access because the situation there is deeply concerning", Jonathan Allen, deputy United Kingdom ambassador to the UN, said.
Another diplomat said however that "no progress" had been made on a joint declaration made in June by the UN Security Council, which called on all warring parties in Yemen to facilitate aid deliveries to the country.
"The longer the conflict goes on, the higher the risk that terrorist groups will spread and the stronger their influence will become", U.N. Yemen mediator Ismail Ould Cheikh Ahmed warned the Security Council.
The humanitarian official urged the global community to ensure that all ports are open to civilian, including to commercial traffic. "In 2017, the number of air strikes per month is three times higher than previous year, and monthly reports of armed clashes are up by more than 50 per cent".
"All of his has not been sharply reversed", he said, noting that 17 million Yemenis are hungry, almost 7 million facing starvation, and about 16 million lack access to water or sanitation.
"This human tragedy is deliberate and wanton - it is political and, with will and with courage which are both in short supply, it is stoppable", he said, reiterating the UN's ongoing calls for a political solution to the conflict.
But he said the United Nations will continue working with Yemenis "to mainstream the language of peace and reach a political solution".
The airport is held by the rebel Houthi fighters who also control the rest of the capital, but airspace over Yemen is dominated by the rival Saudi-led Arab coalition, which is helping the Yemeni government fight the Iran-linked Shia rebels.
In March 2015, a Saudi-led coalition began a campaign in support of Hadi's government and against Houthi forces allied with ousted President Ali Abdullah Saleh. This not only includes the Houthis concentrated in the north but also the southerners who live in the territory the People's Democratic Republic of Yemen (aka South Yemen) governed from 1967-1990.
"We are concerned by the increasing impact on the civilian population, particularly in terms of civilian casualties, fresh displacement and deteriorating conditions", said Shabia Mantoo, UNHCR spokesperson for Yemen.