A mourner touches the body of a Palestinian child killed in Israeli strikes at Abu Yousef Al Najjar Hospital in Rafah. Reuters

"Children who do survive this war will not only bear the visible wounds of traumatic injuries, but the invisible ones too," MSF International Secretary General Christopher Lockyear told the 15-member council.

"There is a repeated displacement, constant fear and witnessing family members literally dismembered before their eyes," he said. "These psychological injuries have led children as young as five to tell us that they would prefer to die."

Lockyear slammed the United States, saying he was appalled it had repeatedly used its veto power to block the council from demanding an immediate humanitarian ceasefire in the war between Israel and Hamas in Gaza.

"The people of Gaza need a ceasefire, not when practicable, but now. They need a sustained ceasefire, not a temporary period of calm," Lockyear said. "Anything short of this is gross negligence."

The US has vetoed three UN Security Council resolutions since the start of the current fighting on Oct.7, most recently blocking on Tuesday a demand for an immediate humanitarian ceasefire as it instead pushes council to call for a temporary ceasefire linked to the release of hostages held by Hamas.

China's UN Ambassador Zhang Jun told the council he felt "appalled" by Lockyear's briefing.

"We hope the tragic picture that he painted of Gaza for us can touch the conscience of a certain member of this council," Zhang said.