SEALs and divers from SEAL Delivery Vehicle Team 1 swimming back to the guided-missile submarine USS Michigan during an exercise. US Navy photo by Mass Communication Specialist 3rd Class Kristopher Kirsop South Korea's Yonhap News Agency reported on Monday that the USS Michigan, a submarine that sometimes moves special forces like US Navy SEALs, would join the USS Carl Vinson aircraft carrier strike group off of North Korea's coast.

Sure enough, on Tuesday, the Michigan, a guided-missile, nuclear-powered submarine, appeared in Busan, South Korea, Fox News reported.

But Yonhap also reported on March 13 that SEAL Team 6 was training alongside South Korea's version of the SEALs for "incapacitating" North Korea's leader, Kim Jong Un.

The US Navy has refused to comment on the movements of SEAL Team 6, the group of Navy SEALs who took out Osama bin Laden in 2011, to Business Insider, and it normally doesn't advertise the whereabouts of its submarines, as the craft are meant to be secretive.

The Pentagon told Business Insider in March that the US did not train for decapitation strikes of any kind, but it would not confirm or deny the presence of the SEALs in Korea.

There has been a flurry of activity on the peninsula recently. Each March, the US and South Korea conduct Foal Eagle and Key Resolve military drills, which bring a wide range of soldiers and platforms to the region.

North Korea also in April celebrates the anniversary of the birth of its founder, Kim Il Sung, and the founding of its army. This year's military parade unveiled an unexpected bounty of new missile types and modifications in North Korea's inventory, with some of them proving particularly troubling for nonproliferation experts.

A North Korean navy truck carries a Pukkuksong submarine-launched ballistic missile in Pyongyang. Thomson Reuters

Meanwhile, the US has signaled a new confidence in its military options against the Kim regime, with President Donald Trump at one point saying, "If China is not going to solve North Korea, we will."

The Michigan adds a stealth element and an extra set of eyes and ears to the already potent carrier strike group on North Korea's coast, but it doesn't add much firepower — US Navy destroyers accompanying the Vinson already have the kind of Tomahawk missiles the Michigan has.

Though the North Koreans have threatened to sink the Vinson, US Pacific Command's Adm. Harry Harris told Congress on Wednesday that as far as North Korea's missile threats to the Vinson go, "If it flies, it will die."

US Navy ships participating in a passing exercise with Indian navy ships. Official US Photograph - US Navy News Stand

But experts have repeatedly stressed to Business Insider that no credible military option against the Kim regime exists.

Even if the US somehow managed to decapitate the Kim regime, the country still technically operates under its "forever leader," Kim Il Sung, who died in 1994.

In the decades since the elder Kim's death, North Koreans have remained fiercely loyal to the regime's goals of nuclear aggression toward the outside world, so it's unlikely a single leader's death would upset that.