Sin, speaking at a rare news conference in New York on Wednesday, was asked if he meant that North Korea would take military action in response to the adoption of any resolution or statement by the council.
"I told you that if any action is taken by Security Council against us, I lose my job," he said.
"Military will have its own job, I mean follow-up. I gave you the answer. You can prejudge what is the meaning I have told you."
Sin also cautioned that the situation on the Korean peninsula remained tense due to what he called the "reckless manoeuvres" of the South.
He said it was "a touch-and-go situation that war may break out at any time", saying that "our people and our army will smash our aggressors".
Delegations from the South and North presented the Security Council on Monday with their positions on the events of March 26.
Claude Heller, the Security Cuncil's president and Mexican ambassador, said after the two separate informal meetings that council members were gravely concerned about the incident and urged both sides to "refrain from any act that could escalate tensions in the region".
He did not say who was to blame.
According to council diplomats, South Korea is hoping the 15-nation body will rebuke the North.
But China, the North's sole major ally, has a veto on the council and is reluctant to support anything that would upset Pyongyang.
Sin reiterated Pyongyang's position that the South's allegations about March 26 are a "complete fabrication" and demanded that the North be allowed to send its own investigation crew to the site of the incident.
"This is indeed a funny story," he said of South Korea's investigation of the sinking. "Some kind of fiction."
"If the South Koreans have nothing to hide, there is no reason for them not to accept our inspection group."
Sin presented a lengthy rebuttal of the South Korean evidence that Seoul says proved the North's military torpedoed the Cheonan.
He suggested that the actual cause of the sinking may have been rocks in the water.
"I am not here to blame anyone but to clarify what happened," he said.
Sin also dismissed the idea that the investigation of the incident was international, saying that the foreign participants played no more than a symbolic role in what was essentially a South Korean investigation.
According to Sin, the evidence against Pyongyang was "fabricated in pursuit of political objectives".
Those objectives included influencing South Korea's recent elections and poisoning North Korea's good ties with China, he said.
The US, Sin said, also benefited politically from the incident, as it helped force Japan to back down from previous demands that the US close a military base on the island of Okinawa.
PJ Crowley, the US state department spokesman, dismissed Sin's comments about a possible military response as "the same kind of provocative behaviour typical of North Korea".