UNITED NATIONS/CAIRO/JERUSALEM, Dec 23 (Reuters) - The U.N. Security Council called for boosting humanitarian assistance for Gaza, but the U.N. chief said the way Israel was conducting its military operation was creating "massive obstacles" to aid distribution inside the battered enclave.

After days of wrangling to avert a threatened U.S. veto, the Security Council on Friday passed a resolutionurging steps to allow “safe, unhindered, and expanded humanitarian access” to Gaza and “conditions for a sustainable cessation” of fighting.

The resolution was toned down from earlier drafts that called for an immediate end to 11 weeks of war and diluting Israeli control over aid deliveries, clearing the way for the vote in which the United States, Israel’s main ally, abstained.

Washington repeatedly has backed Israel’s right to self-defense following the Oct. 7 rampage into Israel by Gaza’s ruling Hamas militants, who killed 1,200 people and took 240 hostages back into the enclave.

Gilad Erdan, Israel’s U.N. ambassador, said the Security Council should have focused more on freeing the hostages and that concentrating on “aid mechanisms” was unnecessary as Israel permits “aid deliveries at the required scale.”

Hamas and the West Bank-based Palestinian Authority split over the measure, with the former saying it was “insufficient” to meet the stricken enclave’s needs and defied international calls for an end to “Israel’s aggression.”

The authority’s foreign ministry welcomed the resolution as a step that would help “end the aggression, ensure the arrival of aid and protect the Palestinian people."

The United States and Israel, which has vowed to eradicate Hamas, oppose a ceasefire, contending it would allow the Islamist militant group to regroup and rearm.

U.S. President Joe Biden’s administration, however, has grown increasingly critical of the mounting casualty toll and humanitarian crisis that has worsened as Israel presses on with its ground and air offensive.

U.N. Secretary General Antonio Guterres said the way Israel is conducting its operation is “creating massive obstacles to the distribution of humanitarian assistance” in Gaza, where the United Nations says the aid available is just 10 percent of what is needed.

Israel says 5,405 aid trucks - bearing food, water and medical supplies - have entered Gaza since the war started.

The latest casualty update from Gaza’s health ministry said 20,057 Palestinians have been killed and 53,320 wounded in the Israeli offensive that has destroyed huge swaths of the enclave and displaced most of the population of 2.3 million.

Israel says 140 of its soldiers have been killed since it launched its ground incursion on Oct. 20.

Photo from Reuters