More than 400 troops took part in a series of exercises – including topless hand-to-hand combat – amid growing fears neighbouring North Korea could be preparing an attack.
Other images show troops doing press-ups, jumping jacks and various other drills in the snow in Pyeongchang, which is just 180km from Seoul.
US and South Korean troops take part in joint winter drills every year but with the Winter Olympics set to begin in February and fears of a North Korean missile launch, this year’s exercises are more important than usual.
The training exercises began on December 4 at the Mount Hwangbyeong training camp as part of the Korea Marine Exercise Program.
A spokesman for the US marine unit, the III US Marine Expeditionary Force, told the news agency: “This exercise has been held with a focus on enhancing the combined combat capabilities of the South Korean and US Marine Corps in winter war conditions under which temperatures drop to about minus 20C.”
The exercises are also an indication of the increasingly close ties between South Korea and the US at a time when tensions on the Korean peninsula continue to escalate.
South Korean Marine Corps Commandant Lt. General Jun Jin-goo told the marines: “You are a symbol of the robust South Korea-US alliance, overcoming the severe cold with comradeship.
“Let’s defend the Republic of Korea (South Korea) firmly on the basis of hot comradeship and strong combat power of the allies’ Marine Corps.”
Meanwhile there are also growing fears North Korea could launch a devastating cyber attack on South Korea during next year’s Winter Olympics.
The reclusive regime, led by Kim Jong-un, has covertly trained an army of 6,000 computer hackers over the past decade.
US tech expert Priscilla Moriuchi warned that tyrant Kim wants use his hacker army to spark “chaos” in South Korea.
She said: “There is definitely a strong thread throughout these attacks of a North Korean connection through the malware and, it seems, through the techniques that they’re using.
“That desire to target South Korea and create chaos that would undermine South Korea’s image is still very much a goal for North Korea.
“It’s more likely that they would do something in the cyber operations sphere.”