North Korea claims U.S. submarine visit to South Korea is a ‘rehearsal’ for further deployment

I mean... They hold an annual "rehearsal" about going to war with the North. What exactly are they trying to claim here?

We've been parking boats down there pretty frequently for like 40 years. I made a week long port call there on a boat [SSN 711] around 2012 - it was in their [South Korea's] news papers. This is just North K. blowing hot air. We conduct joint exercises with them faily regularly in the yellow sea.