North Korea is currently working on an “aggressive schedule” to develop a ballistic missile submarine capable of reaching the United States, the website 38 North, run by the Johns Hopkins School of Advanced International Studies has revealed.

“Commercial satellite imagery of the Sinpo South Shipyard from November 5 indicates that North Korea is on an aggressive schedule to build and deploy its first operational ballistic missile submarine,” the website claims.

Images posted to the website indicate an active shipbuilding operation at the Sinpo South Shipyard, known for its production of large submarines for the North Korean navy.

The website adds that the shipyard has “the presence of what appear to be sections of a submarine’s pressure hull in the yards suggests construction of a new submarine, possibly the SINPO-C ballistic missile submarine.”

Developing such a watercraft would be a natural continuation of North’s current ballistic missile submarine, which is experimental in nature, the note continued.

The developments will further concern the White House, days after President Donald Trump completed his tour of Asia where he discussed the North Korean crisis with the region’s leaders, particularly Chinese President Xi Jinping, who Trump has called on to do more to solve the crisis.

Following the visit, Chinese announced it would send a special envoy to North Korea, although the country’s foreign ministry claimed the visit was routine.

North Korea’s last successful nuclear test took place in September of an immensely powerful hydrogen bomb, while officials in South Korea and Japan have warned that their capacity to use nuclear weapons is “imminent.”

Trump has previously claimed that further aggression from North Korea could force the United States into a military response that would “totally destroy” the hermit state, adding that “rocket man” Kim Jong-un is on a “suicide mission.”

However, a recent analysis by the Pentagon determined a ground invasion of North Korea would be the “only way” to fully disarm the country of its nuclear arsenal.

On Wednesday, North Korea state television said that Trump had been “sentenced to death by the Korean people” for insulting Kim Jong-un on Twitter:

“The worst crime for which he can never be pardoned is that he dared malignantly hurt the dignity of the supreme leadership of the DPRK,” an editorial by North Korea’s state-run newspaper Rodong Sinmun read.

“Trump, who is no more than an old slave of money, dared point an accusing finger at the sun. He should know that he is just a hideous criminal sentenced to death by the Korean people.”

Follow Ben Kew on Facebook, Twitter at @ben_kew, or email him at bkew@breitbart.com.