The Palais Princier released a statement on Tuesday ahead of festivities, which read: "Their Serene Highnesses have both decided that a period of calm and rest is necessary to ensure the very best recovery for Princess Charlene's health.
"Having battled with poor health over the past few months, the Princess is currently convalescing and will continue to do so for the coming weeks, allowing her time to recover from a state of profound general fatigue. In order to protect the comfort and privacy essential to her recovery, the Princess' location will remain strictly confidential."
WATCH: Princess Charlene and Prince Albert share highlights from their relationship
It continued: "Due to this situation, the Princely couple regrets to announce that Princess Charlene will be unable to attend this year's Fête Nationale (National Day) celebrations, alongside her family and the people of Monaco. As soon as her health permits, the Princess looks forward to once again carrying out her Princely duties and spending time with the Monegasques.
"During this temporary period of rest, the Princely couple kindly requests that their privacy and family environment are well respected. Information on the Princess' health will be communicated in due course, ahead of the Christmas holidays."
Charlene, 43, made her return to Monaco last week after spending six months grounded in South Africa due to an ear-nose-throat (ENT) infection.
She was reunited with her husband and their six-year-old twins, Prince Jacques and Princess Gabriella, at Nice airport before travelling home to the Prince's Palace.
Charlene's last public engagement in Monaco in January
It comes after Prince Albert had told PEOPLE magazine that he hoped his wife would join him at Dubai's World Expo on 13 November, as well as Monaco's National Day. However, the royal, 63, travelled to Dubai without Charlene over the weekend, attending with his sister, Princess Stephanie, and her son, Louis Ducruet, instead.
There have been reports that Charlene may move into a two-bedroom above an old chocolate factory instead of the Prince's Palace. However, the princess' sister-in-law, Chantell Wittstock, has refuted these claims.
Speaking to South Africa's Channel24 last week, the charity director, who is married to Charlene's brother, Sean Wittstock, said: "The princess is extremely happy to be back home with her family," before reiterating: "She will be staying with her husband and children."
Make sure you never miss a ROYAL story! Sign up to our newsletter to get all of our celebrity, royal and lifestyle news delivered directly to your inbox.