Buckingham Palace announced Thursday that Queen Elizabeth II is under “medical supervision” at Balmoral Castle.
“Following further evaluation this morning, The Queen’s doctors are concerned for Her Majesty’s health and have recommended she remain under medical supervision,” Buckingham Palace said in a statement.
Buckingham Palace did not specify what was causing the concern. The Royal Family added that the Queen is “comfortable” at the residence.
Earlier this year, the 96-year-old celebrated her Platinum Jubilee but was forced to miss some of the festivities due to health concerns.
Earlier this week, she accepted the resignation of outgoing British Prime Minister Boris Johnson. Later the same day, she met with new Prime Minister Liz Truss.
"The whole country will be deeply concerned by the news from Buckingham Palace this lunchtime," Truss said in a midday tweet. "My thoughts - and the thoughts of people across our United Kingdom - are with Her Majesty The Queen and her family at this time."
CNN reported that the Queen's son Prince Charles and the Queen's grandson Prince William have traveled to Balmoral.
BBC News reported that the Queen canceled a meeting Wednesday evening of the Privy Council. The outlet said she was advised to rest following a "full day" of activities on Tuesday, which included meetings with Johnson and Truss.