Queen Elizabeth's Platinum Jubilee 2022: Queen says she is 'deeply touched' by jubilee celebration

Queen Elizabeth II will miss out on what was expected to be one of the highlights of her Platinum Jubilee, a National Service of Thanksgiving in her honor.

The 96-year-old queen will not attend Friday’s service at St. Paul’s Cathedral in London, Buckingham Palace announced.

“The Queen greatly enjoyed today’s Birthday Parade and Flypast but did experience some discomfort,” the palace said in a statement. “Taking into account the journey and activity required to participate in tomorrow’s National Service of Thanksgiving at St Paul’s Cathedral, Her Majesty with great reluctance has concluded that she will not attend.”

The queen, “would like to thank all those who made today such a memorable occasion,” the statement concluded.

The palace has previously said the queen suffers from “episodic mobility problems.”

She appeared in good spirits Thursday while watching the Trooping the Color parade and the military flypast from the balcony of Buckingham Palace.

Thursday's Trooping the Color though marked the first time in her 70-year reign that Elizabeth has given the royal salute from the palace’s balcony. Her oldest child and heir, Prince Charles, took the royal salute on the parade ground and inspected the troops in her place.

Prince Andrew, the second-oldest son of Queen Elizabeth II, has tested positive for COVID-19, a royal source told ABC News.

Andrew’s diagnosis comes as the queen celebrates her Platinum Jubilee, marking 70 years on the throne. He was expected to join the royal family Friday at a national service of thanksgiving at St. Paul’s Cathedral, but will no longer attend, according to the royal source.

“After undertaking a routine test The Duke has tested positive for Covid and with regret will no longer be attending tomorrow’s service,” said the source.

As expected, Andrew did not appear with the royal family Thursday at Trooping the Color because he is no longer an active senior royal, including having returned his military titles and royal patronages to the queen earlier this year.

In February, Andrew agreed to settle a sexual assault lawsuit.

President Joe Biden and first lady Dr. Jill Biden tweeted a video message congratulating the Queen.

"Your Majesty, congratulations on your Platinum Jubilee. For 70 years, you've inspired people with your selfless devotion and service to the people of the United Kingdom and the Commonwealth," Biden said. "Throughout your reign, the relationship between the United Kingdom and the United States has grown stronger and closer than ever."

The first lady added her own well-wishes. "Throughout the years, the joy your visits to the United States have brought Americans, and your solidarity with the American people in times of tragedy, have deepened the friendship and profound connection between our countries," she said. "And Joe and I were so touched by the generosity and welcome you showed to us when we visited you at Windsor Castle last year, during our first visit overseas as President and First Lady."

"Congratulations, Your Majesty, and have a wonderful Platinum Jubilee celebration," she added.

They are 92 years apart in age, but Queen Elizabeth, 96, and her great-grandson, Prince Louis, 4, appear to share a close bond.

The queen was seen answering Louis’s questions and pointing things out to him while the two watched military jets fly overhead on the balcony of Buckingham Palace at the end of Trooping the Color.

Louis, one of the queen’s nine great-grandchildren, is the youngest child of Prince William and Kate, Duchess of Cambridge.

He joined his siblings, Prince George and Princess Charlotte, on the balcony and, earlier, in a carriage to travel to Buckingham Palace.