Prince Harry took part in 24-hour cold chamber training with the British Walking With The Wounded South Pole Allied Challenge team.
A soldier is hoping to become the first double amputee to walk to the South Pole in a team made up of wounded servicemen and women.
Prince Harry has described five wounded soldiers who attempted to climb to the peak of Mount Everest as "extraordinary".
Prince Harry has said the Walking With The Wounded expedition hopes to arrive at the South Pole on Friday 13 - "unlucky for some, lucky for us".
The adventurers are nearing the end of their 200-mile trek across Antarctica with their goal almost in sight.
Harry, who is patron of the expedition, said: "A half day on Friday and we get to the South Pole on Friday 13th , unlucky for some, lucky for us.
"The wind has dropped down, which is nice. I think everyone is feeling a bit tired but slowly getting into the rhythm. Only just got into the rhythm now and it has almost finished."
The 29-year-old prince has already said spirits are really high following the decision to suspend the competitive element of the trek.
Harry was part of a British group racing to the South Pole against teams from the Commonwealth and the US.
But the competition was stopped over the weekend after some of the adventurers, who include injured servicemen and women, became very tired after encountering difficult terrain.
The race to the South Pole - in which Prince Harry is taking part - has been suspended.
But tonight the adventure - across 200 miles of some of the most inhospitable terrain on earth - goes on.
The organisers - the Walking with the Wounded charity - say they took the decision to stop the competition for "safety" reasons.
But as ITV News Correspondent Harry Smith reports, although the race is over, the three teams still hope to get there in the end:
Prince Harry's race to the South Pole with Walking With The Wounded has been suspended for safety reasons, expedition director Ed Parker said.
The decision to suspend the race element was made after a "very tricky" few days of unexpectedly difficult conditions that has exhausted the competitors.
Team members on the Walking with the Wounded South Pole trek will now work together to reach the South Pole - the race element has been taken out of the challenge. Guy Disney, from Team Glenfiddich said:
The first four days was a full out slog. It really tested every single individual mentally and physically. We are about 112 km from the South Pole and we all can’t wait to get there as one big group.
The race has been suspended due to safety concerns arising from the adverse weather conditions.
Prince Harry's charity trek to the South Pole has been suspended due to safety concerns arising from the adverse weather conditions.
"We have put the race on hold. This does not mean that the expedition is over. Far from it. We came down here, determined to get 12 men and women, all injured in conflict, to the South Pole, and so we will," the expedition director Ed Parker said.
The team members will move as one whole allied team to reach the South Pole together. Each evening, the expedition will be camping together. They should reach the South Pole by next weekend.
"I took the decision to suspend the race. The reason for this is entirely simple – safety, which remains the core principal of our expeditions," Ed Parker, the expedition director said.
Prince Harry could not resist engaging in some playful banter when he offered his support to a group of soldiers rowing across the Atlantic in a satellite call conversation from Antarctica.
Harry is taking part in Virgin Money South Pole Allied Challenge - a gruelling charity trek to the South Pole, racing with a team of injured British servicemen and women against United States and Commonwealth groups in an expedition organised by the Walking With The Wounded charity.
The group set off on their 300km mission on Sunday but before doing so, Harry found the time to offer his support to the Row2Recovery team ahead of their 3,000 nautical mile race from the Canary Islands to Antigua, which starts on Wednesday.
Organisers of the South Pole charity trek, which Harry is taking part in, said they are shortening the start line to ensure the race is completed by the 15th December.
Today the decision has been taken by Edward Parker, Team Noom Coach Mentor and Co-Founder of Walking With The Wounded, to move the racestart 60km nearer to the South Pole.
His decision ensures the race a safewindow to arrive at the Geographical South Pole by 15 December.
– Walking with the wounded statement
This decision, given that recent adverse weather may well continue, has been considered eminently sensible by the three polar guides on the expedition: Inge Solheim, Conrad Dickinson and Eric Philips.
The expedition is now in the process of being moved by the support vehicle approximately 60km closer to the finish line, which reduces the overall race distance.
[...] Team spirits are high and everyone is working together in the lead up to the race start, which is expected to be on Sunday 1 December.
Prince Harry's charity trek to the South Pole has been shortened by 60km (37 miles) because of adverse weather.
The race, which will now be 163 miles long, will begin on Sunday. The 29-year-old is taking part with wounded service personnel in aid of the military charity Walking with the Wounded.