But organisers announced on Thursday that it would not go ahead as planned and would likely be rescheduled to May or June 2021.
Harry, who is quitting as a senior royal at the end of the month, was set to travel to the Netherlands with the Duchess of Sussex to attend the event.
Our Patron the #DukeofSussex has released a video message to the #InvictusGames competitors recognising their disappointment at the news, but that it's the best outcome for their safety and recovery. #CoronavirusUpdate #IG2020 https://t.co/STbVVpILeC— Invictus Games Foundation (@WeAreInvictus)March 19, 2020
In a video posted to the Invictus Games Foundation Twitter account, he said: "This was an incredibly difficult decision for all of us to have had to make.
"I’m so grateful for everybody who has worked so incredibly hard over the last couple of week to try and find any alternative to try and carry out these games, in a different way and in a safe way.
“But this decision was the most sensible and the safest option for all of you and your families as well as everybody else involved in these games."
He continued: “I know how disappointed you all must be. This is a focus that so many of you need.
"I would encourage you to maintain that focus as best you can.
“The good thing is 12 or so months to be even fitter, to get even fitter than you already are and be at your absolute top mental and physical fitness so in that sense I am really excited about the games next year."
Harry went on to apologise for not being able to hold the annual competition, which brings together current and former wounded, injured or sick servicemen and women from more than 20 countries.
He said: “Please take care of yourselves, but do what you do best which is reaching out to other people, be it those that still wear the uniform, use to wear the uniform or just those people in your community who you know may be suffering or may be vulnerable during this period.
“Do what you do best and we will do everything that we can to get you a date and a time for you to show up next year. You’ll be the first to know.
“Again really sorry we couldn’t make this happened. But take care of yourselves and I’ll catch up with you soon.”
In a statement, the Invictus Games Foundation said: "The decision was also taken in recognition of the anticipated strain on medical staff and the infrastructure required in dealing with the pandemic.
"We did not wish to add to the complexity of the response, or increase the risk to those involved, by bringing together an international and potentially vulnerable audience."
It added: "We are now investigating all options to reschedule the Invictus Games, subject to the availability of key facilities and resources, to May or June 2021. Significant planning to scope and confirm this option is under way."
Harry has attended all the Invictus Games since the first in London in 2014. His wife Meghan has joined him at the Toronto and Sydney Invictus Games.
Meghan’s visit to the Invictus Games in Toronto was her first public appearance with Harry since the news of their relationship broke.
The Duke of Sussex will continue to play a key part in the games after he steps back from his duties as a senior royal.