Mental health is a cause close to Prince Harry and Meghan Markle's heart, and the couple has often championed the significance of mental health awareness in the society.

In the latest, Prince Harry and Meghan Markle crashed a virtual staff meeting of a crisis text line, a mental health texting service, to encourage them as they deal with an increasing number of cases amid coronavirus pandemic.

The Duke and the Duchess of Sussex, who are isolating with their son Archie at their home in California, made a surprise appearance during a Crisis Help Line team meeting to thank the staff and offer words of encouragement.

According to Town&Country magazine, one of the staff had shared a screenshot of the video conference call which showed the Sussexes in a new corner of their untold Los Angeles home, but he has since made his Twitter account private and the post is no longer publicly accessible.

The Crisis Text Line was established in 2013 to provide free, 24/7 support to those in need of it, and has processed more than 100 million messages until now. Harry and Meghan along with Prince William and Kate Middleton, had helped launch a UK-based sister program like Crisis Help Line last year.

The Sussexes and the Cambridges had released a joint statement to announce the launch of the helpline named "Shout," in which they stated: "We are incredibly excited to be launching this service, knowing it has the potential to reach thousands of vulnerable people every day. Over the last few months, Shout has started working quietly behind the scenes."

The surprise video call comes weeks after Harry launched a mental health fitness project titled HeadFIT to help servicemen and women, in partnership with the U.K. Ministry of Defence and King's College London, as well as the Royal Foundation's Heads Together campaign. The new philanthropic project launched last month provides 24/7 access to mental health resources for armed forces personnel overseas in the form of exercises and counseling.

meghan markle
Loved-up: Prince Harry and Meghan Markle arrive to a walkabout at Cardiff Castle on January 18, 2018 in Cardiff, Wales Getty

The project which has been in making for three years was due to be unveiled in June, but the launch was preponed to help military personnel deal with the challenges during the coronavirus pandemic.