The monster nuclear submarine the US sent to South Korea looks like it might be packed with Navy SEALs

The US Navy maintains that the USS Michigan, a submarine known for carrying special-ops teams, stopped in South Korea's Busan as part of a "routine port visit," but pictures of the event suggest a more clandestine purpose that may involve US Navy SEALs.

On top of the Michigan as it arrived in Busan appeared to be two silos for SEAL Delivery Vehicles (SDV), or tiny submarines used to transport US Navy SEALs and their equipment for their most covert missions deep in enemy territory.

The Navy confirmed to Business Insider that these pods are used by Naval Special Warfare units, but as a rule it does not disclose deployments of Navy SEALs.

In April, when the Michigan last visited Busan, South Korean media reported that it carried SEALs to train with South Korean forces for a "decapitation" mission, in which the US and South Korea would work together to kill Kim Jong Un and take out North Korea's nuclear command structure.

However, the US military maintains it does not train for decapitation missions or attempts at regime change of any kind and does not typically comment on SEAL deployments.

Now, as the US and North Korea trade nuclear threats and the US and South Korea gear up for another round of military drills, the Michigan has returned, sending a powerful message. The Michigan, a nuclear-powered submarine, used to carry nuclear missiles but now carries 150 Tomahawk precision-guided missiles.

The US only operates four such submarines, known as SSGNs, and rarely discusses their whereabouts.

In 2011, when the US initiated conflict with Libya, it was the USS Florida, a fellow SSGN, that kicked off operations by launching more than 90 Tomahawks at targets in Libya, beating down Libyan defenses before airpower and surface ships took control of the situation.

With not one but two SDV silos attached, the Michigan could potentially deliver a considerable number of highly mobile, covert SEALs to South Korea. Silos add drag and decrease the stealthiness of the Michigan, suggesting they were included for a reason.

Additionally, as the US continues efforts to put "maximum pressure" on North Korea, Yonhap News posted pictures of F-22 Raptor stealth jets training for an air show in South Korea.

Experts have told Business insider that the ultra-stealth F-22 fits the profile of the type of weapon the US would use in the early salvos of fighting with North Korea.

On Sunday, Secretary of State Rex Tillerson again asserted that the US will continue diplomatic efforts with North Korea "until the first bomb drops," as President Donald Trump repeatedly hints at using force to solve the crisis.

Despite the outward appearance of war preparations, the Trump administration's aggressive approach to North Korea has yielded economic and diplomatic results. China has now gone further than ever before in sanctioning North Korea, and a handful of other important nations have also cut ties.

Trump is scheduled to visit South Korea in November.