(CNN) -- The race to the South Pole is off -- although the trek still continues for Prince Harry and teams of wounded veterans.
Ed Parker, the expedition director of the Virgin Money South Pole Allied Challenge, revealed Saturday that he'd made the decision to call off the competition among three teams to reach the pole after five days.
"The reason for this is entirely simple -- safety, which remains the core principal of our expeditions," Parker said in a statement.
It wasn't bad weather that led to the decision, and Parker even said that "all three teams were progressing well" over the first five days. Rather, it was the fact that the mission -- especially as a competition -- was putting undue strain on the participants.
"It was becoming evident that there was a higher degree of stress imposed on the team members, due to unprecedented terrain on the plateau," said Parker, a former British soldier who co-founded Walking With The Wounded in 2010.
Prince Harry -- himself a member of Britain's armed forces, having served in Afghanistan and elsewhere -- has had a long association with this charity.
In several ways, he's been preparing for this latest mission for a long time. That includes taking part in a Walking With The Wounded expedition to the North Pole -- even plunging into the Arctic Ocean's freezing waters -- in 2011 before withdrawing to attend his brother William's wedding. More recently, he traveled to Iceland for training and even spent 24 hours in an industrial freezer in preparation for the South Pole race.
Yet, while Harry may be the only royal in Antarctica, he's hardly the only celebrity.
Swedish actor and "True Blood" star Alexander Skarsgard is an honorary member of the U.S. team, while Dominic West, perhaps best known for his role as McNulty in "The Wire," joins veterans wounded in combat from the Commonwealth nations of Canada and Australia.
Still, the stars -- and focus of the event -- are the veterans themselves. The three teams of seven participants each represent the United Kingdom, United States and the Commonwealth, which consists of several countries long affiliated with the British empire.
The plan was to trek more than 200 miles (322 kilometers) across the sparse continent, in temperatures as low as -35 degrees Celsius (-31 Fahrenheit).
And that's still the plan; it's just that they won't be racing.
The participants on Sunday are set to resuming the walk, hoping to traverse the 70 remaining miles to the South Pole "with no stress being placed on the teams ... enabling them all to do this in their own time," Parker explained.
Parker said he expects them all to reach that, by Friday or Saturday of next week, all of them will be at the finish "celebrating."
CNN's Pierre Meilhan, Max Foster and Susannah Cullinane contributed to this report.