Actor Pierce Brosnan has said he deeply regrets walking off trail in Yellowstone national park in the western US after he was fined by a court in Wyoming for getting too close to one of the delicate thermal areas

Brosnan, 70, pleaded guilty to foot travel in a thermal area and was fined $500 and required to pay a $1,000 community service payment to the Yellowstone Forever Geological Fund, the US attorney’s office, district of Wyoming, said on Thursday.

Citing court documents, it said the James Bond actor had in November uploaded photos to Instagram of himself “standing on a Yellowstone National Park thermal feature at Mammoth Hot Springs”, referring to the scenic area in the park’s northern part.

“There are signs posted in the area that warn visitors of the dangers of thermal features and state that visitors must remain on the designated boardwalks and trails,” it said.

Walking off trail in such thermal areas can be perilous as the ground is fragile and the water extremely hot.

Posting on his Instagram page late on Thursday, Brosnan said he was “an environmentalist” who had “the utmost respect for and love of our natural world”.

“However, I made an impulsive mistake – one that I do not take lightly – when entering a thermal area covered in snow in Yellowstone National Park to take a photograph. I did not see a No Trespassing sign posted that warned of danger nor did I hike in the immediate area,” he wrote.

“I deeply regret my transgression and offer my heartfelt apologies to all for trespassing in this sensitive area. Yellowstone and all our National Parks are to be cared for and preserved for all to enjoy.” He added #StayOnThePath.

Brosnan is known for playing the suave 007 agent in four James Bond films from 1995 to 2002 as well as for his roles in the Mamma Mia movies, The Thomas Crown Affair and most recently Black Adam.

Yellowstone features the Old Faithful sky-high geyser that spouts forth frequently and hundreds of bubbling and boiling, spraying and spouting hot pools of water and mud, often with strong sulfurous smells.

The park is also known for its wild bison, with officials warning visitors to stay away from the animals after incidents when tourists got too close, sometimes trying for dramatic selfie photos.

Reuters contributed reporting