Translation:
=====START HERE=====
To BOA, the admiral of the American Navy:

Currently your fleet is closing in on the vicinity of our fleet.  We regard
this as a violation of the sovereign territory of the Great Imperial Japan.
 We hereby issue a warning to turn back and retreat.  Otherwise, your
actions will be met with force which will mean the complete destruction of
your fleet.  We trust that you will make the appropriate decision.

Jordi
Admiral
Imperial Japanese Navy

<FD>
Director
Intelligence & Propaganda Department
Imperial Japanese Navy
=====END HERE=====