UNITED NATIONS (Reuters) - A quarter of Yemen’s people are on the brink of famine, parents are marrying off young daughters so someone else can care for them and cholera cases are escalating, U.N. officials warned on Tuesday as they work to avert a Saudi-led attack on a key port.

Slideshow ( 2 images )

The United Nations has warned the Arab alliance fighting Iran-aligned Houthis against any attempt to extend the war to Hodeidah, a vital Red Sea aid delivery point where some 80 percent of Yemen’s food imports arrive.

“An attack on Hodeidah is not in the interest of any party, as it will directly and irrevocably drive the Yemeni population further into starvation and famine,” U.N. aid chief Stephen O’Brien told the U.N. Security Council, urging all U.N. member states to help keep the port open and operating.

“Yemen now has the ignominy of being the world’s largest food security crisis with more than 17 million people who are food insecure, 6.8 million of whom are one step away from famine. Crisis is not coming, it is not even looming, it is here today,” he said.

The Saudi-led coalition has said it was determined to help Yemen’s government retake all areas held by Houthi militia, including Hodeidah port, but would ensure alternative entry routes for badly needed food and medicine.

U.N. Yemen envoy Ismail Ould Cheikh Ahmed told the Security Council on Tuesday he had made clear to the parties to the conflict that they must reach a compromise to avoid the “horrific scenario” of military action moving to the port.

However, he noted the Houthis and the allied General People’s Congress, the party of former President Ali Abdullah Saleh, did not meet with him in the capital Sanaa to discuss a possible agreement that he had proposed.

O’Brien said a $2.1 billion humanitarian strategy and plan for Yemen was only a quarter funded.

“Yemen is not facing a drought. If there was no conflict ... a famine would certainly be avoidable and averted,” he said. “Families are increasingly marrying off their young daughters to have someone else to care for them, and often use the dowry to pay for basic necessities.”

O’Brien also said there had been some 55,000 suspected cases of cholera since April and estimated another 150,000 cases were expected over the next six months.

“Had the parties to the conflict cared, the outbreak was avoidable,” O’Brien said.