Seoul, Apr 25 (IANS): An American guided-missile submarine, the USS Michigan, arrived in South Korea on Tuesday, the same day Pyongyang is celebrating the 85th anniversary of the founding of its Korean People's Army, the media reported.

The US Navy submarine arrived in the port city of Busan, reports CNN.

A statement from US Naval Forces Korea called the submarine's visit "routine" and said it was a chance to highlight the alliance between American and South Korean navies.

While the USS Michigan is not expected to take part in the ongoing joint exercises, its presence in the region is meant to send a strong message to Pyongyang, the statement added.

Earlier this month, President Donald Trump had said that the US was sending an "armada" with submarines to the region.

"We are sending an armada. Very powerful," Trump said in a Fox News interview.

"We have submarines. Very powerful. Far more powerful than the aircraft carrier."

Armed with tactical missiles and equipped with superior communications capabilities, the 560-foot-long, 18,000-tonne Michigan is one of four converted Ohio-class subs, joining the USS Ohio, USS Florida and USS Georgia, reports CNN.

Each of the four submarines can carry up to 154 Tomahawk cruise missiles.

They are also outfitted to stealthily deploy up to 66 Navy servicemen or other special operations troops and their equipment.

The Michigan's visit to Busan comes after North Korea on Sunday threatened to sink the American aircraft carrier USS Carl Vinson, which is beginning joint drills with two Japanese destroyers in the western Pacific Ocean.