I hope that's an exaggeration.
It may not be, but the statement could also be read as an indictment of the condition of our power grid. This administration seems to have made every effort to get as many power plants off the grid as possible, and make it as difficult as possible to add new ones, so it might not take much to bring the whole grid down.
Ask yourself, what would happen to our nuclear power plants in an EMP attack? I'll go with total meltdown - across the country.
I doubt it.
Keep in mind, that North Korea is a proxy for the Chinese military, which is drooling at the prospect of attacking the U.S....but doesn't want to be counter-attacked. Hence the use of a decoy nation. Which we have been altogether too lame about accepting as an "independent" just regarding it as a "friend" of China's.... not the puppet it is.
We should be telling the Chicoms that if North Korea attacks us...they will be held directly responsible...first and foremost.
We have devices on the ground to nullify such a strike for the most part, kind of like grouding a house.
They could do some damage but not lots of it.