Doctors are "concerned for Her Majesty's health," Buckingham Palace announced on Thursday, as members of the royal family rushed to Scotland to be with the 96-year-old queen.

The palace declined to disclose any information on the severity of the queen's illness. Still, there were other alarming indications, such as Prime Minister Liz Truss's statement that "the entire country will be deeply concerned by the news" and other politicians' expressions of unease.

The palace made the statement a day after the queen canceled a virtual meeting of her Privy Council after doctors urged her to rest following a busy day on Tuesday, during which she formally asked Truss to become prime minister.

"Following further evaluation this morning, the Queen’s doctors are concerned for Her Majesty’s health and have recommended she remain under medical supervision," a palace spokesperson said, speaking on the condition of anonymity as is customary. "The Queen remains comfortable and at Balmoral."

Prince Charles, his wife Camilla, and his sister Princess Anne are already at Balmoral Castle, the queen's summer palace in Scotland, with the queen. The eldest son of Prince Charles, Prince William, is also en route to Balmoral, together with his brother, Prince Harry, his wife, Meghan, Prince Andrew, and the Earl and Countess of Wessex.

The meeting of the House of Windsor occurred barely three months after the 70th anniversary of the queen's accession to the throne was commemorated with a national holiday. Buckingham Palace streets were crowded with shouting, flag-waving admirers for four days. Still, the queen made only two brief appearances on the palace balcony to wave to her citizens.

In recent months, Elizabeth has delegated more responsibilities to Charles and other royal family members as she recovers from COVID-19, begins using a cane, and struggles to move around.

"The whole country will be deeply concerned by the news from Buckingham Palace this lunchtime," tweeted Truss.

“My thoughts — and those of people across our United Kingdom — are with Her Majesty The Queen and her family at this time.

Since she acceded to the throne on February 6, 1952, following her father's death, Elizabeth has been a symbol of stability as Britain navigated the end of its empire, the beginning of the information age, and colossal migration that has turned the country into a multicultural society.

The queen has forged a bond with the nation through a seemingly endless series of public appearances in which she opened libraries, dedicated hospitals, and showered honors on deserving residents.

She worked diligently until the end of her reign. The death of Prince Philip, her husband of more than 70 years, in April of last year, however, served as a reminder to the United Kingdom that the reign of the queen, the only monarch most of her subjects have ever known, is finite.

This was the underlying theme of the Platinum Jubilee celebrations, as newspapers, television news programs, and even the palace walls were filled with images of Elizabeth as she transformed from a glamorous young queen in a crown and diamonds to a kind of global grandmother known for her ever-present handbag and love of horses and corgis.

Charles was in the spotlight throughout the festivities, representing his mother and demonstrating his readiness to assume her mantle.

On the opening day of the jubilee, he reviewed the troops at the Queen's Birthday Parade while wearing a traditional scarlet tunic and bearskin headgear. The following day, he was the last guest to enter St. Paul's Cathedral and sat in the first row for a thanksgiving service in honor of the queen. At a star-studded concert in front of Buckingham Palace, he paid tribute to the woman he referred to as "Your Majesty, mummy."