Harry maintains his cool as he is warned of -40C temperature on trip to North Pole

The 26-year-old royal attended a briefing after he was greeted by the team from Walking With The Wounded, and heard about his training for the next three days.

He is expected to play a full part in the final preparations for the expedition, including sleeping out on the ice and dragging a 100kg sled.

On Friday the prince will fly out to the start point of the 200-mile trek.

Asked if he was ready for the challenge, Harry said: “Not as ready as these guys are, but I’m just here to give them as much support as possible. I haven’t had as much time to train.”

He added, jokingly: “But today, to their huge amusement, they’re going to see me on a pair of, whatever they’re called, skis, this afternoon.

“So it should be entertaining for all of us.”

Harry is patron of the Walking With The Wounded charity which aims to raise £2m from the unaided trek to help other injured servicemen and women find work, peace of mind and security.

During the briefing in Longyearbyen on the Norwegian island of Spitsbergen, team leader Inge Solheim said polar bears were known to be in the area.

One had been chased away from the town just two days ago.

On its first day the team will ski for seven and a half miles (12kms) pulling sleds known as pulks, weighing around 220lbs (100kg).

Mr Solheim told the team: “It’s going to be around minus 25C today, so it’s quite mild and good, nothing like we’re going to get in the polar ocean.

“Hopefully out there we’ll get minus 35C to minus 40C with good stable high pressure.”

Harry winced as he heard the extreme temperatures.

The four wounded servicemen, who sustained their injuries fighting in Afghanistan, will be joined by the two co-founders of the Walking With The Wounded charity, Captain Martin Hewitt, 30, from Cheshire, and Captain Guy Disney, 29, from Oxford.