Queen Elizabeth II dies

Queen Elizabeth II, Britain's longest-reigning monarch, died at Balmoral Castle, Scotland on Thursday afternoon, at age 96, Buckingham Palace said.

Her 73-year-old son Prince Charles will become Britain's new monarch, but he will be known as King Charles III, according to royal officials. Charles' second wife, Camilla, will be known as the Queen Consort.

Charles called the death of the queen "a moment of the greatest sadness for me and all members of my family … I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world", according to a statement.

Britain's Prime Minister Liz Truss, appointed by the queen on Tuesday, said the country was "devastated" and called Elizabeth "the rock on which modern Britain was built".

"It's an extraordinary achievement to have presided with such dignity and grace for 70 years," she said. "Her life of service stretched beyond most of our living memories."

UN Secretary-General Antonio Guterres said: "As the United Kingdom's longest-lived and longest-reigning head of state, Queen Elizabeth II was widely admired for her grace, dignity, and dedication around the world."