This work is in the public domain in the U.S. because it is an edict of a government, local or foreign. See § 313.6(C)(2) of the Compendium of U.S. Copyright Office Practices, 3rd ed. 2014 (Compendium (Third)). Such documents include "legislative enactments, judicial decisions, administrative rulings, public ordinances, or similar types of official legal materials."
These do not include works first published by the United Nations or any of its specialized agencies, or by the Organization of American States. See Compendium (Third) § 313.6(C)(2) and 17 U.S.C. § 104(b)(5).
A non-American governmental edict may still be copyrighted outside the U.S. Similarly, the above U.S. Copyright Office Practice does not prevent U.S. states or localities from holding copyright abroad, depending on foreign copyright laws and regulations.