UN Security Council envoys spoke of unimaginable suffering and urged an end to the war in the Gaza Strip on Monday as they headed across Egypt's Sinai Peninsula to the Rafah crossing, the besieged Palestinian enclave's only entry point for aid.

China's representative to the United Nations Zhang Jun, asked by reporters if he had a message to nations which opposed a ceasefire in Gaza, said simply: "Enough is enough."

A majority of United Nations member states support an immediate and lasting ceasefire between Israel and the Palestinian terrorist group Hamas, which controls Gaza, as dire conditions worsen for its 2.3 million residents.

The United States, which backs Israel, last week vetoed a proposed Security Council demand for an immediate ceasefire as Israeli tanks and troops press an invasion that has displaced most of Gaza's population and killed more than 18,000 people.

A dozen UN Security Council envoys attended the trip organized by the United Arab Emirates to visit Rafah, just days after Secretary-General Antonio Guterres warned that thousands of people in the besieged Palestinian enclave were "simply starving."

After flying to the town of Al-Arish they were briefed by UN Palestinian refugee agency UNRWA on conditions in Gaza before heading towards Rafah 30 miles (48 km)away.

"The reality is even worse than what words can speak," Ecuador's UN representative Jose De La Gasca told reporters after the UNRWA briefing.

"We need to see...we will witness what is happening and what can we do in order to address the situation," he said.

Israel has bombarded Gaza from the air and from land, imposed a siege and mounted a ground offensive in retaliation for an Oct. 7 attack by Hamas that Israel says killed 1,200 people and saw 240 people taken hostage. Gaza health authorities say about 18,000 people have been killed by Israeli attacks, with 49,500 injured.

The vast majority of the Palestinian enclave's 2.3 million people have been driven from their homes.

UNRWA chief Philippe Lazzarini described an "implosion of civil order" where Gazans who have not eaten for days looted aid distribution centers and stopped trucks on roads as they tried to secure supplies for their families.

"There is not enough assistance," Lazzarini said. "Hunger is prevailing in Gaza...most of the people are just sleeping on the concrete."

Limited humanitarian aid and fuel deliveries have crossed into Gaza via the Rafah crossing, but aid officials say it comes nowhere near to satisfying the most basic needs of Gazans.

The 15-member Security Council is negotiating a UAE-drafted resolution that demands warring parties "allow the use of all land, sea and air routes to and throughout" Gaza for aid.

It would also establish a UN-run aid monitoring mechanism in Gaza Strip. It was not clear when the draft resolution could be put to a vote.

Guterres last week formally warned the Security Council of the global threat to peace and security posed by the conflict.

He told it that half of Gazans in the north of the territory and at least a third of those displaced in the south were "simply starving" and later criticized it for having "failed" to help bring about a humanitarian ceasefire.

The UN General Assembly will meet on Gaza on Tuesday at the request of Arab and Muslim states. The 193-member body is likely to vote on a draft resolution demanding an immediate humanitarian ceasefire, diplomats said.

The UN Office for the Coordination of Humanitarian Affairs said that 100 trucks carrying humanitarian supplies entered Gaza from Egypt on Sunday, the same number as the previous day.

It noted that was "well below" the daily average of 500 truckloads, including fuel, that entered every working day prior to Oct. 7.

A UNICEF employee, speaking to reporters on the condition of anonymity, said the logistics center near Al-Arish was storing items Israel had banned from being sent into Gaza, including solar panels and an ultrasound machine. The employee said they were banned because they were electrical and contained metal.