A POWERFUL US sub has arrived in South Korea amid worries of another North Korean missile or nuclear test as Kim Jong-un carries out huge war games.
The USS Michigan - capable of firing off salvos of Tomahawk cruise missiles - is to join the aircraft carrier USS Carl Vinson in drills near the Korean Peninsula.
The sub belongs to the Ohio class of boats which are the biggest of their kind ever to be built for the US Navy.
North Korea celebrates its army's 85th founding anniversary today and reports suggest it has marked the event with its "largest ever firing drill".
It is feared the anniversary will be marked with the testing of a nuclear device or a ballistic missile.
But instead North Korea deployed a large number of long-range artillery units in the region of Wonsan on its east coast for a live-fire drill, South Korea's military said.
North Korea has an air base here and missiles have also been tested there.
What kind of submarine is the USS Michigan?
The 560-foot-long, 18,000-ton Michigan is the biggest class of submarine in the US Navy and belongs to the Ohion class.
It began service as a ballistic missile submarine and loaded with nuclear missiles.
But during the 2000s it was converted to platform for conventional weapons and it’s firepower is awesome.
It can carry 154 Tomahawk cruise missiles at any one time.
Superior communications capabilities mean it can accurately hit its targets within minutes of being ordered to strike.
Sisters subs include USS Ohio, USS Florida and USS Georgia.
The boat will join the USS Carl Vinson Carrier Strike Group in the Sea of Japan amid fears war will break out between North and South Korea.
MOST READ IN NEWS
The South's Office of Joint Chiefs of Staff said in a statement: "North Korea is conducting a large-scale firing drill in Wonsan areas this afternoon."
The South Korean military was monitoring the situation and "firmly maintaining readiness", it said.
Meanwhile its navy said it was conducting a live-fire exercise with US destroyers today in waters west of the Korean peninsula and would soon join the carrier strike group approaching the region.
With tensions reaching boiling point, top envoys from South Korea, Japan and the United States met in Tokyo to discuss how to respond.
North Korea's growing nuclear and missile threat is perhaps the most serious security challenge confronting U.S. President Donald Trump.
Trump has vowed to prevent North Korea from being able to hit the United States with a nuclear missile and has said all options are on the table, including a military strike.
We pay for your stories! Do you have a story for The Sun Online news team? Email us at [email protected] or call 0207 782 4368