The queen has been advised to take a "short period of rest," according to a palace spokesperson.

Queen Camilla will sit out her planned public engagements this week due to illness, Buckingham Palace says.

"Her Majesty The Queen is currently unwell with a chest infection, for which her doctors have advised a short period of rest," a palace spokesperson said in a statement on Nov. 5.

"With great regret, Her Majesty has therefore had to withdraw from her engagements for this week, but she very much hopes to be recovered in time to attend this weekend's Remembrance events as normal," the statement continued. "She apologizes to all those who may be inconvenienced or disappointed as a result."

The queen, 77, had been scheduled to attend the Field of Remembrance opening ceremony at London's Westminster Abbey on Nov. 7. The annual commemoration invites people to plant a poppy to honor those who lost their lives in the Armed Forces.

Camilla is patron of The Poppy Factory, the charity that has organized the Field of Remembrance ceremony since 1928.

Birgitte, Duchess of Gloucester, will stand in for the queen at this year's Field of Remembrance event. The duchess is a full-time working member of the royal family, and is married to the late Queen Elizabeth's cousin, the Duke of Gloucester.

Camilla will also no longer be able to attend a reception for Olympic and Paralympic medalists scheduled for Nov. 7 at Buckingham Palace. The queen had been set to co-host the event with her husband, King Charles III.

The king and queen recently returned from a royal tour in Australia and Samoa. This was the king's first major overseas tour since beginning treatment for cancer, according to Sky News.

In February, Buckingham Palace revealed that Charles had been diagnosed with an undisclosed form of cancer. He began outpatient treatment on Feb. 5, the palace said, and he returned to his public-facing royal duties in April.