Saudi Arabia's King Salman has called in his Ramadan message for the international community to bring an end to the "heinous crimes" taking place in Gaza, where Israel's war with Hamas has been raging for more than five months.

Speaking as custodian of Islam's two holiest sites, King Salman gave thanks on Sunday for the "blessings bestowed upon the Kingdom of Saudi Arabia", but noted the war in besieged Gaza would cast a shadow over the holy month of fasting and prayer.

"As we witness the arrival of Ramadan this year, our hearts are heavy with sorrow for the ongoing suffering of our Palestinian brothers facing relentless aggression," he said.

"We call upon the international community to uphold its responsibilities to put an end to these heinous crimes and ensure the establishment of safe humanitarian and relief corridors."

Gaza is in the midst of a spiralling humanitarian crisis after months of war sparked by Hamas's unprecedented October 7 attacks on Israel.

Aid groups say only a fraction of the supplies required to meet basic humanitarian needs have been allowed into the territory since Israel placed it under a near-total siege.