TORONTO -- Kensington Palace has released an adorable video of the Duke and Duchess of Cambridge’s three children giving an enthusiastic round of applause to frontline health-care workers.

At 8 p.m. British time on Thursday, people across the U.K. clapped from their front doors, gardens or balconies in a show of support for the country’s National Health Service (NHS) staff battling the COVID-19 pandemic.

Prince William and Catherine and a number of other senior royals took to Instagram to show solidarity with healthcare workers using the hashtag #clapforcarers, joining millions of others across the U.K.

Their kids, Princess Charlotte, in a stripey shirt, little Prince Louis in a bright blue sweater and Prince George in a navy blue polo, clap in unison as the camera zooms in.

“To all the doctors, nurses, carers, GPs, pharmacists, volunteers and other NHS staff working tirelessly to help those affected by #COVID19: thank you,” the caption reads.

The Queen’s Instagram account shared a 17-second video of the outside of Windsor Castle where a trumpet is heard, people cheer and others bang pots and pans.

The previous post, which features a collage of the Queen meeting medical workers, had a message for the NHS.

“We are enormously thankful for the expertise and commitment of our scientists, medical practitioners and emergency and public services,” the caption read.

Prince Charles, who has tested positive for COVID-19 and is self-isolating at a royal estate in Scotland, appears in a Clarence House Instagram story where he is also seen applauding.

Charles’ brother Prince Edward and his wife Sophie, Countess of Wessex, and their children also feature on The Royal Family Instagram page with a “huge thank you to so many of you working on the frontline, we really appreciate it, keep up the fantastic work.”

Meanwhile, British Prime Minister Boris Johnson said Friday he has tested positive for the new coronavirus, but remains in charge of the U.K.'s response to the outbreak.

"I'm working from home and self-isolating and that's entirely the right thing to do,” Johnson said in a video on his Twitter account.

"But, be in no doubt that I can continue thanks to the wizardry of modern technology to communicate with all my top team to lead the national fight-back against coronavirus.

"I want to thank everybody involved and, of course, our amazing NHS staff."

According to Johns Hopkins University, which curates a map tracking coronavirus cases internationally, more than 11,816 cases of COVID-19 have been confirmed in the U.K. and 578 people who tested positive for the respiratory infection have died.

- With files from The Associated Press