Sqoon

Aliens who rule the planet Neptune realize that they have run out of their primary source of nutrition, "man-ham livestock," and decide to invade Earth to feed off the humans. They melt the polar ice caps, causing entire continents to sink under the ocean. The General of the Earth Defense Army begs a pirate called Narikeen to strike back at the aliens with his submarine, Sqoon. Narikeen, being of an evil nature, laughs at the pleas of the general, but reluctantly agrees to exterminate the aliens.

However in the Japanese version, the message came from the United States of America's Pentagon and the message says in Romaji:

SOS...SOS... OTOTOSEIJIN NO SHINRYAKU ARI KYSOKU NI KAIMEN JOSYOSERI SQOON SYUTSUGEKI SEYO KAITEI NI HEIWAO!

U.S.A. PENTAGON