North Korea threatened to sink a US nuclear sub currently deployed in South Korean waters if the US take provocative action, responding to a statement from Donald Trump that the president won’t be “happy” if Pyongyang conducts another nuclear test.

After the US deployed a nuclear-powered submarine and an aircraft carrier to South Korean waters amid high Korean tensions, Yonhap reported that North Korea on Sunday threatened to sink the submarine, accusing America of stepping up military intimidation.

"The moment the USS Michigan tries to budge even a little, it will be doomed to face the miserable fate of becoming a underwater ghost without being able to come to the surface," the North's propaganda website Uriminzokkiri wrote in a vivid article. North Korea’s nuclear deterrent will assure that American aircraft carriers, nuclear submarines, and other military hardware will be “shattered into pieces of molten metal” if they threaten Pyongyang, the article read.

The North warned - once again using its dramatically vivid jingoist language - that "whether it's a nuclear aircraft carrier or a nuclear submarine, they will be turned into a mass of scrap metal in front of our invincible military power centered on the self-defense nuclear deterrence."

"The urgent fielding of the nuclear submarine in the waters off the Korean Peninsula, timed to coincide with the deployment of the super aircraft carrier strike group, is intended to further intensify military threats toward our republic," the website further claimed. According to the article, recent statements from the Trump administration indicate that Washington is close to implementing a strategic scenario in which an actual military confrontation is a real possibility.

Earlier on Sunday, Donald Trump told CBS that he “will not be happy” if North Korea conducts another nuclear test. When asked to clarify, the US president said: “I would not be happy. If he (North Korean supreme leader, Kim Jong-un) does a nuclear test, I will not be happy.”

“And I can tell you also, I don’t believe that the president of China, who is a very respected man, will be happy either,” Trump said, adding that he believes Xi Jinping was also “putting pressure” on North Korea to bring a halt to its nuclear tests.

CBS host John Dickerson then directly asked Trump whether US military action was possible, the US president replied: “I don’t know. I mean, we’ll see.”

The guided-missile submarine USS Michigan sailed into the South Korean port of Busan on April 25 before heading out to sea four days later. The Ohio-class submarine is reportedly conducting various drills. At the same time, the U.S. has also directed the nuclear-powered aircraft carrier USS Carl Vinson to the waters near South Korea. The supercarrier is currently engaged in a joint exercise with South Korean naval forces of the Korean peninsula.

The threat followed North Korea's failed missile launch. On early Saturday, North Korea fired off a ballistic missile which the South Korean military said exploded after flying only 71 kilometers. The launch marks the third missile test in April.

Trump told CBS that the failed test wasn’t significant enough to warrant action against North Korea. “This was a small missile. This was not a big missile. This was not a nuclear test, which he was expected to do three days ago. We’ll see what happens,” the president said.

Joint US-South Korean naval wargames, Foal Eagle, involving 20,000 Korean and nearly 10,000 American troops kicked off in the region on Sunday.

Washington has said that the USS Carl Vinson aircraft carrier and USS Michigan nuclear sub will remain in the area due to the spike in tensions between Washington and Pyongyang.