The King has been briefed at Buckingham Palace by aid agencies on the growing humanitarian crisis in Gaza.
Charity leaders from Medical Aid for Palestinians, the British Red Cross, Unicef UK and Christian Aid met with the monarch in-person on Thursday.
Charles, who is president of the British Red Cross, discussed the “acute humanitarian situation” in the region, a Buckingham Palace spokesperson said.
The British Red Cross said the King had made a “generous donation” to its fundraising appeal.
“We are immensely grateful to HM King Charles for his generous donation to our Israel and Occupied Palestinian Territory appeal,” the charity wrote on social media.
Aid agencies are calling for a ceasefire in the Israel-Hamas conflict to protect civilians and humanitarian workers, and ensure safe and sustained access to aid.
Prime Minister Rishi Sunak has stressed the need for temporary breaks in the bombings to allow Israeli hostages and British nationals to be freed.
Buckingham Palace did not comment on whether the King discussed the plight of the hostages and the work to free them during the private meeting.
But the International Committee of the Red Cross, in its neutral intermediary role, assisted with the recent release of four Israeli hostages. Hamas is still holding more than 200 people.
At the audience were the chief executive of Unicef UK Jon Sparkes, Medical Aid for Palestinians chief executive Melanie Ward, vice chair of the board of trustees for Medical Aid for Palestinians Shireen Jayyusi, Christian Aid chief executive Patrick Watt, and Rory Moylan, head of region for the Middle East, North Africa and Europe at the British Red Cross.
The British Red Cross has described the situation in Gaza as an “unprecedented humanitarian crisis” with vital resources unable to get through.
It said the most pressing issue is the lack of food and water, and that recent aid convoys were just “a drop in the ocean”.
Israel has only in recent days agreed to allow aid into Gaza, having besieged the Hamas-ruled area, preventing essentials such as water, food and fuel from reaching more than two million Palestinians.
But the UN has warned it is on the verge of running out of fuel in the Gaza Strip, forcing it to sharply curtail relief efforts in the territory.
The King also held an audience with the Crown Prince of Kuwait on Wednesday when he also discussed the ongoing conflict, which has already claimed nearly 8,000 lives on both sides.
Israeli prime minister Benjamin Netanyahu has said the military is preparing for a full-scale ground invasion to crush Hamas.
In a landmark speech last week, Charles stressed the “vital” need for mutual understanding among religions in times of “international turmoil and heart-breaking loss of life”.
Earlier in the month, he held talks with Sir Ephraim Mirvis, the Chief Rabbi, at the Palace to discuss the horrors of events in Israel and how to support interfaith harmony in Britain in distressing and difficult times.
Buckingham Palace said Charles condemned Hamas’s “barbaric acts of terrorism” after its October 7 attack on Israel – which killed 1,400 people.
