It's King Charles III Now & He Says Queen Elizabeth II's Loss 'Will Be Deeply Felt'

The newly named King Charles III mourned his mother Queen Elizabeth II in a brief statement on Thursday, less than an hour after Buckingham Palace announced that she'd died at age 96.

"The death of my beloved Mother, Her Majesty The Queen, is a moment of the greatest sadness for me and all members of my family," he said in the statement.

"We mourn profoundly the passing of a cherished Sovereign and a much-loved Mother. I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world."

Charles added that he and his family will be "comforted and sustained by our knowledge of the respect and deep affection in which The Queen was so widely held."

Charles has the option to choose a new name for himself as king, but new British Prime Minister Liz Truss seemed to let the name slip in her own statement about the queen's death.

Truss named him as "King Charles III" in her speech, which also paid tribute to the late queen.

"Queen Elizabeth II was the rock on which modern Britain was built," Truss said. "She was the very spirit of Great Britain, and that spirit will endure."

"God save the king," she added.

Truss only just recently became prime minister and now finds herself in the middle of perhaps the biggest shift in her country's history on her third day in office.

Queen Elizabeth II's last official act was to appoint Truss as the PM on Tuesday. The queen cancelled events due to her health on Wednesday and died Thursday at Balmoral Castle, surrounded by many members of the royal family.

Truss dropped the name before anyone else, but Clarence House later confirmed it in a statement to the BBC and others.