UN Secretary-General Antonio Guterres has called for "silencing the guns" in Gaza to honour the spirit of the holy month of Ramadan.
Guterres told reporters that Ramadan celebrates "peace, reconciliation and solidarity. Yet even though Ramadan has begun - the killing, bombing and bloodshed continue in Gaza".
"The eyes of the world are watching us, history is watching us, and we cannot turn a blind eye," he added.
He also called for the release of hostages held by Hamas and the removal of "all obstacles to ensure the delivery of lifesaving aid at the speed and massive scale required" to Gaza, where the UN has warned that a quarter of the population are on the brink of famine.
"International humanitarian law lies in tatters," he told reporters. "And a threatened Israeli assault on Rafah could plummet the people of Gaza into an even deeper circle of hell."
In an interview, Israeli Prime Minister Benjamin Netanyahu said the Israeli army would enter Rafah: "We will go there, we will not leave them... I have a red line, do you know what it is? May the 7th of October never be repeated."
According to reports, diplomatic efforts will be accelerated over the next 10 days to reach a ceasefire agreement during the first half of Ramadan.
The war, triggered by Hamas' attack on Israel on October 7, has resulted in the deaths of 31,112 Palestinians, according to the health ministry in Gaza.