"X Games" star Jackson Strong is calling out ESPN for canceling an upcoming snowmobile freestyle competition -- the incredibly dangerous sport that cost Caleb Moore his life 3 weeks ago in Aspen.

Action sports athletes have been mum since ESPN pulled the plug on the freestyle demo -- scheduled for next month in France -- but Jackson tells TMZ he thinks that's a big mistake ... and not at all what his friend Caleb would want.

Jackson, aka "Jacko," says ... “Personally, I don’t think he would have been impressed if they were to cancel the contest. Anyone in 'X Games' or action sports knows the risk they are taking.”

Caleb died on Jan. 31 from injuries he suffered while attempting to backflip his 450 lb. snowmobile. ESPN says it's continuing to review snowmobile freestyle ... but some critics think it should be eliminated altogether.

21-year-old Jacko had his own 'X Games' brush with death while trying a freakish move called "The Jack" (below at 1:00) -- and admits there are huge risks when stunts go wrong ... but "everybody is pumped when it goes right.”
 


That might sound like a cavalier attitude considering we're talking life or death -- but Jacko says, "Anybody truly involved in action sports is to going to do it no matter what. If people don’t [like it], then they can go suck a d**k.”  

So, we gotta ask ...

A 25-year-old professional snowmobiler has died from injuries he sustained during a horrific crash during the Aspen X Games last week.

Caleb Moore passed away this morning in Colorado, a family spokesperson said.

Moore's family declined to release further details about the death, but stated on Sunday that he had suffered a "brain complication" stemming from the accident ... on top of a severe concussion and bleeding of the heart.

Moore was competing at the snowmobile freestyle final last Thursday when his 450-pound snowmobile flipped over and landed on top of him.

ESPN released a statement Tuesday, saying, "We've worked closely on safety issues with athletes, course designers and other experts for each of the 18 years of X Games. Still, when the world's best compete at the highest level in any sport, risks remain."

Caleb -- once an avid all-terrain vehicle rider -- was a 4-time X Games medalist who first began competing in 2010, after just one month of practicing on snowmobiles.