The host of TV programme Running Wild, Bear Grylls, has said President Obama told him filming his show in Alaska was one of the best days of his presidency.
Wilderness expert Mr Grylls shared details of the US president's day of filming in Alaska for the NBC show.
The trip showed an "intimate" and "fun" side of Mr Obama that is not often seen, said Mr Grylls.
They visited Alaska's shrinking Exit Glacier in an episode focused on climate change.
The duo also discussed fatherhood, fears, and what it is like to live in a "bubble" separated from average people.
"There were times along the route I had to pinch myself and think, actually, this is the president of America," Mr Grylls told reporters in New York, according to Reuters.
The White House pitched the idea for the episode, he said, and he is the first sitting president to take part in the show.
"They approached us, saying would we consider taking the president on an adventure to Alaska. I almost really didn't believe it. I thought it was a spoof," said Mr Grylls.
Fifty Secret Service personnel, a food taster, snipers and helicopters came along with the duo as they filmed in Alaska, he said.
Mr Grylls said Mr Obama lit fires, ate berries and shared his water bottle.
In a clip from the episode, Mr Grylls and Mr Obama cook and eat a wild salmon that a bear had already taken a few bites out of.
"The president looked a little surprised when I pulled out this bloody carcass of half-eaten salmon," said Mr Grylls.
Mr Obama called him a "mediocre cook" and said "it would've been nice if we had a cracker to go with the salmon".
The episode airs for the first time in the US on 17 December.