The revival of the multibillion-dollar effort, known as the Integrated Undersea Surveillance System (IUSS), comes as China has ramped up military exercises around Taiwan.
Submarine No. 841 - named Hero Kim Kun Ok after a North Korean historical figure - will be one of the main "underwater offensive means of the naval force" of North Korea, leader Kim Jong Un said.
Tehran’s comments appear to be a warning to the US that Iran could encourage proxy groups to continue to target Americans in Syria.
Yasen-class submarines are nuclear-powered cruise missile submarines, built to replace Soviet-era nuclear attack submarines.
The reports come amid heightened tensions on the Korean peninsula as South Korea and the United States take steps to boost military readiness against North Korea's weapons program.
The USS Annapolis entered a naval base in South Korea' southern island of Jeju, to load military supplies while on an unspecified operational mission, the South Korean navy said.
“US SSBNs anywhere from the US West coast westward can strike targets in North Korea,” Van Diepen said. “Therefore, some US SSBNs are within range of North Korea at all times.”
No regulatory bodies had approved of the Titan, as recorded by the waiver which also stated that the sub was "constructed of materials that have not been widely used for manned submersibles."
"There is no guarantee that a shocking incident where a US air force strategic reconnaissance plane is shot down over the East Sea will not happen," the spokesperson said.
The sections of the Titanic that did not implode were able to do so because the air had been released from within, equalizing the pressure inside and out of the ship.