The US military Tuesday vehemently denied a media report that special forces had been parachuted into North Korea on intelligence-gathering missions, saying a source had been misquoted.

Current affairs magazine The Diplomat quoted Brigadier General Neil Tolley, commander of special forces in South Korea, as saying soldiers from the US and South Korea had been dropped across the border for "special reconnaissance" missions.

But Colonel Jonathan Withington, public affairs officer for US Forces Korea, said some reporting of the conference had taken Tolley "completely out of context".

"Quotes have been made up and attributed to him," he said, denying that any US or South Korean forces had parachuted into the North.

"Though special reconnaissance is a core special operations force (SOF) mission, at no time have SOF forces been sent to the north to conduct special reconnaissance," he said in a statement.

The Diplomat quoted Tolley as saying that the North had built thousands of tunnels since the 1950-53 Korean War.

"The entire tunnel infrastructure is hidden from our satellites," the magazine reported him as saying at a press conference in Florida last week. "So we send (South Korean) soldiers and US soldiers to the North to do special reconnaissance."

According to the magazine, he said commandos parachute in with minimal supplies to watch the tunnels undetected.

At least four of the tunnels built by Pyongyang go under the Demilitarized Zone separating North and South Korea, Tolley was reported as saying. "We don't know how many we don't know about."