King Charles Tells Prime Minister Liz Truss That Queen's Death Is 'Moment I've Been Dreading'

Diplomatic duties begin for King Charles III.

The monarch, 73, met with newly elected Prime Minister Liz Truss at Buckingham Palace in London Friday, marking their first formal meeting in their new roles.

"It's very kind of you to come in. I know how you've been busy, to say the least," King Charles told the new premier with a laugh.

On a more somber note, he said that the outpouring of sympathies following his mother's death meant so much.

"It's been so touching, this afternoon, when we arrived," he said of the tributes he and his wife Camilla, Queen Consort, found in London. "All those people had come to give their condolences and put flowers… it's the moment I've been dreading, as I know a lot of people have," he continued, alluding to Her Majesty's death. "But we'll try to keep everything going."

Truss, 47, met Queen Elizabeth at Balmoral Castle on Tuesday, following her election as leader of the Conservative Party. She became the 15th – and final – prime minister appointed by the Queen.

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The audience was historic, as it marked the first time in the Queen's record-breaking 70-year reign that she did not meet a new premier in England. Queen Elizabeth had been experiencing episodic mobility issues, and a source told PEOPLE the appointment was hosted at Balmoral for certainty of schedules.

Charles and his wife, now known as Camilla, Queen Consort, had traveled to Queen Elizabeth's side in the Scottish Highlands after Buckingham Palace announced that her doctors were "concerned" for Her Majesty's health Thursday. Charles had been in Scotland the day before, carrying out engagements.

There, the senior royals joined by Princess Anne, Prince William, Prince Andrew, Prince Edward, his wife, Sophie, Countess of Wessex and Prince Harry, who is in Europe this week with wife Meghan Markle for a series of charity visits.

On Thursday, Buckingham Palace announced that Queen Elizabeth died at age 96, at her beloved Balmoral Castle.

"The Queen died peacefully at Balmoral this afternoon," officials said in a statement. "The King and The Queen Consort will remain at Balmoral this evening and will return to London tomorrow."

After the news was announced, Truss paid tribute to the late royal while helping usher in a new era with King Charles' pending succession.

"Queen Elizabeth II was the rock on which modern Britain was built. Our country has grown and flourished under her reign," the prime minister said in a statement shared to social media.

"In the difficult days ahead, we will come together with our friends across the United Kingdom, the Commonwealth and the world to celebrate her extraordinary lifetime of service," Truss continued. "It is a day of great loss, but Queen Elizabeth II leaves a great legacy."

"God save the King," she concluded.

On Friday evening, King Charles addressed the nation — and the world — in his first speech as monarch.