Saudi Arabia’s Crown Prince Mohammed bin Salman has accused Israel of carrying out “collective genocide” in Gaza, in some of his strongest criticism of the country since the war began last year.

"The Kingdom renews its condemnation and categorical rejection of the genocide committed by Israel against the brotherly Palestinian people," Crown Prince Mohammed bin Salman said at an Arab Islamic summit, echoing comments by Saudi Foreign Minister Faisal bin Farhan Al Saud late last month.

Saudi Arabia's de facto ruler on Monday called on Israel to respect Iran's sovereignty and refrain from attacking Iranian soil, highlighting warming ties between the Middle East rivals.

Saudi Crown Prince Mohammed bin Salman said Monday that Israel was committing "genocide" against Palestinians and urged the international community to halt the country's "attacks on the Palestinian and Lebanese peoples.

The Saudi Crown Prince was speaking at a summit of Muslim and Arab leaders and also criticised Israeli strikes on Lebanon and Iran.