Nearly four years after stepping away as senior working royals, the Duke and Duchess of Sussex are set to land in Nigeria later today (Friday) for a three-day visit.

Shortly after spending some time in the UK for the Invictus Games' 10th anniversary, which ended with a Service of Thanksgiving at St. Paul's Cathedral in London, Prince Harry and his wife are to visit the West African country for the first time.

Their planned visit will kick off with the Chief of Defense Staff and a visit to a local school. The prince will also meet with injured servicemembers at a military hospital, a spokesperson for the Sussexes confirmed to ABC News.

While in London, Harry surprised a group of children at Scotty's Little Soldiers, a charity that supports bereaved military kids.

"It was an honour to meet so many of the wonderful families Scotty's Little Soldiers supports," said Harry.

"I have long believed in the mission of this charity, and I truly believe the work they do to foster community and create space for young people to connect, grieve, but also have fun together is life-changing. I am a huge supporter of their work, and very proud to be their first Global Ambassador."

In keeping with the ethos of the Invictus Games, the 38-year-old and Meghan are due to attend a training session for Nigeria: Unconquered, and a reception hosted by the Chief of Defence Staff in honour of military families on Saturday, PEOPLE magazine reported.

Meghan will then co-host a Women in Leadership event with Dr Ngozi Okonjo-Iweala, Director General of the World Trade Organisation.