The country has been hammered by years of war, hunger and disease. Is the world prepared to watch it “fall off the cliff?” a United Nations official asks.

International donors pledged about $1.35 billion in humanitarian aid for Yemen on Tuesday, far short of the $2.4 billion the United Nations had said was needed to pull a country shredded by years of war, hunger and disease from the brink of further disaster.

Mark Lowcock, the United Nations’ emergency relief coordinator, was blunt about the results of the donor conference, which was hosted, virtually, by Saudi Arabia.

“We cannot be satisfied where we got to today,” he said. In addition, he noted that the money raised had not yet been paid, only promised.

Funding had withered this year over donors’ concerns that the Houthis, the Iran-backed armed group that controls northern Yemen, were interfering with aid distributed in their territory. The Houthis have since made some concessions to allow aid to flow more freely, said Lise Grande, the United Nations’ top official in Yemen.

United Nations officials warned that without more donations, nearly 400 hospitals and health care centers it finances would have to reduce services just as the coronavirus pandemic has surged in Yemen. Already, food rations have been halved for 8.5 million hungry Yemenis, and 10,000 health care workers have lost the United Nations payments that for many are their only salary, Ms. Grande said.

Since the war began five years ago, pitting the Houthis against a government backed by Saudi Arabia and the United Arab Emirates, Yemenis have endured doomsday after doomsday: relentless airstrikes against hospitals and schools by the Saudi-led military coalition using American-made weapons, a severe cholera outbreak, the ever-present threat of famine, a health care system in collapse and now the coronavirus.

“Yemenis themselves say things are worse today than at any time in their recent history,” Mr. Lowcock said in his appeal to donors, asking “whether the world is prepared to watch Yemen fall off the cliff.”

Though Covid-19 deaths appear to be multiplying quickly across Yemen, Yemeni authorities have done little to check the virus’s spread. The Houthis, in the north, have denied the outbreak’s existence; their enemies, battling for dominance of the south, are too weak and divided to respond.

As the pandemic bore down, Saudi Arabia, which has poured tens of billions of dollars into the war to little tangible end, announced a unilateral cease-fire in Yemen in early April. But that has not prevented conflict from erupting in the weeks since, as the Houthis continue to mount attacks, a separatist group battles the internationally recognized government for control in the south, and bombs from the Saudi-led coalition keep falling.

Aid groups urged all sides on Tuesday to negotiate an end to the war — the only real hope of resolving Yemen’s many humanitarian crises. And critics of Saudi Arabia said the fortune it had spent on aid for Yemen, including the $500 million it pledged on Tuesday, meant little if it continued to bomb civilians and blockade supplies from reaching Houthi territory.

“Saudi Arabia keeps trying to whitewash its coalition’s role in the deepening humanitarian catastrophe in Yemen, but co-hosting the funding event won’t fool anyone,” said Afrah Nasser, the Yemen researcher at Human Rights Watch. The Saudi-led coalition and the Houthis, she said, “should immediately cease violating the laws of war and put an end to the humanitarian crisis in Yemen for which they’re all responsible.”

Jan Egeland, the secretary general of the Norwegian Relief Council, an aid group that works in Yemen, said that millions of Yemenis were “staring down the double barrel of starvation and a global pandemic.”

He urged donors to reach deep into their pockets, adding, “But money alone is not enough. These pledges are worth little if people are still fleeing from bombs and crossfire and their hospitals attacked.”

Even as he issued his appeal, the hostilities marched on.

On Monday, a spokesman for the Saudi-led coalition, Col. Turki al-Malki, said the Saudis had intercepted two Houthi drone strikes aimed at civilian targets across the border in Saudi Arabia. And on Tuesday, soon after Saudi Arabia trumpeted its hosting of the donor conference in a series of news releases, the Houthis said that Saudi Arabia had launched several airstrikes on its territory.