This is the list of NATO country codes. Up to and including the seventh edition of STANAG 1059, these were two-letter codes. The eighth edition introduces three-letter codes to resolve the conflicts with the ISO 3166-1 standard, which it adopts with a single exception : for diplomatic reasons, Macedonia is designated as the « Former Yugoslav Republic of Macedonia » and receives a code different from the ISO one.

AC  ATG Antigua and Barbuda
AF  AFG Afghanistan
AG  DZA  Algeria
AJ  AZE Azerbaijan
AL  ALB Albania
AM  ARM Armenia
AN  AND Andorra
AO  AGO Angola
AR  ARG Argentina
AS  AUS  Australia
AU  AUT Austria
BA  BHR  Bahrein
BB  BRB Barbados
BC  BWA Botswana
BE  BEL Belgium
BF  BHS The Bahamas
BG  BGD  Bangladesh
BH  BLZ  Belize
BK  BIH Bosnia-Herzegovina
BL  BOL  Bolivia
BM  MMR Myanmar
BN  BEN Benin
BO  BLR  Belarus
BP  SLB  Solomon Islands
BR  BRA  Brazil
BT  BTN  Buthan
BU  BGR  Bulgaria
BX  BRN  Brunei
BY  BDI  Burundi
CA  CAN Canada
CB  KHM  Cambodia
CD  TCD Chad
CE  LKA  Sri Lanka
CF  COG Republic of the Congo
CG  COD Democratic Republic of the Congo
CH  CHN China (People's Republic of China)
CI  CHL Chile
CM  CMR  Cameroun
CN  COM Comoros
CO  COL  Colombia
CS  CRI Costa Rica
CT  CAF Central African Republic
CU  CUB  Cuba
CV  CPV Cape Verde
CY  CYP Cyprus
CZ  CZE  Czech Republic
DA  DNK  Denmark
DJ  DJI  Djibouti
DO  DMA Dominica
DR  DOM Dominican Republic
EC  ECU Ecuador
EG  EGY  Egypt
EI  IRL Ireland
EK  GNQ  Equatorial Guinea
EN  EST Estonia
ER  ERI  Eritrea 
ES  SLV  El Salvador
ET  ETH Ethiopia
FI  FIN  Finland
FJ  FJI  Fiji
FR  FRA France
FY  FYR Macedonia, The Former Yugoslav Republic of (the ISO 3166 code is MKD)
GA  GMB The Gambia
GB  GAB Gabon
GC  n/a East Germany (obsolete 1990)
GE  DEU Germany
GG  GEO Georgia
GH  GHA  Ghana
GJ  GRD Grenada
GR  GRC Greece
GT  GTM  Guatemala
GV  GIN  Guinea
GY  GUY  Guyana
HA  HTI  Haiti
HO  HND Honduras
HR  HRV  Croatia
HU  HUN  Hungary
IC  ISL Iceland
ID  IDN Indonesia
IN  IND India
IR  IRN Iran
IS  ISR Israel
IT  ITA Italy
IV  CIV Côte d'Ivoire
IZ   IRQ Iraq
JA  JPN Japan
JM  JAM  Jamaica
JO  JOR  Jordan
KE  KEN Kenya
KG  KGZ  Kirghizstan
KN  PRK Democratic People's Republic of Korea
KR  KIR  Kiribati
KS  KOR  Republic of Korea
KU  KWT  Kuwait
KZ  KAZ  Kazakhstan
LA  LAO  Laos
LE   LBN  Lebanon
LG  LVA  Latvia
LH  LTU Lithuania
LI  LBR Liberia
LO  SVK Slovakia
LS  LIE Liechtenstein
LT  LSO Lesotho
LU  LUX Luxemburg
LY  LBY  Libya
MA  MDG Madagascar
—   FSM Federated States of Micronesia
MD  MDA Republic of Moldova
MG  MNG Mongolia
MI  MWI  Malawi
ML  MLI  Mali
MN  MCO Monaco
MO  MAR  Morocco
MP  MUS  Mauritius
MR  MRT Mauritania
—   MNP  Northern Mariana Islands
—   MHL  Marshall Islands
MT  MLT  Malta
MU  OMN  Oman
MV  MDV  The Maldives
MX  MEX Mexico
MY  MYS  Malaysia
MZ  MOZ  Mozambique
NG  NER  Niger
NH  VUT  Vanuatu
NI  NGA Nigeria
NL  NLD Netherlands
NO  NOR Norway
NP  NPL  Nepal
NR  NRU  Nauru
NS  SUR  Suriname
NU  NIC Nicaragua
NZ  NZL  New Zealand
PA  PRY  Paraguay
PE  PER  Peru
PK  PAK Pakistan
PL  POL  Poland
PM  PAN Panama
PO  PRT Portugal
PP  PNG Papua New Guinea
PU  GNB Guinea-Bissau
—   PLW  Palau
QA  QAT  Qatar
RO  ROU  Romania
RP  PHL Philippines
RQ   PRI Puerto Rico (the only non-sovereign nation in the list)
RS  RUS  Russia
RW  RWA  Rwanda
SA  SAU  Saudi Arabia
SC  KNA  Saint Kitts and Nevis
SE  SYC  Seychelles
SF  ZAF  South Africa
SG  SEN  Senegal 
SI  SVN Slovenia
SL  SLE Sierra Leone
SM  SMR San Marino
SN  SGP Singapore
SO  SOM Somalia
SP  ESP Spain
ST  LCA Saint Lucia
SU  SDN  Sudan
SW  SWE  Sweden
SY  SYR Syria
SZ  CHE  Switzerland
TC  ARE  United Arab Emirates
TD  TTO  Trinidad and Tobago
—   TLS Timor-Leste
TH  THA  Thailand
TI  TJK  Tadjikistan
TN  TON  Tonga
TO  TGO  Togo
TP  STP São Tomé and Príncipe
TS  TUN  Tunisia
TU  TUR  Turkey
TV  TUV  Tuvalu
TW  TWN  Taiwan (Republic of China)
TX  TKM  Turkmenistan
TZ  TZN  Tanzania
UG  UGA Uganda
UK  GBR United Kingdom (Great Britain)
UP  UKR  Ukraine
UR  n/a Union of Soviet Socialist Republics (obsolete 1992)
US  USA United States
UV  BFA Burkina Faso
UY  URY Uruguay
UZ  UZB  Uzbekistan
VC  VCT Saint Vincent and the Grenadines
VE  VEN  Venezuela
VM  VNM Viet Nam
VT  VAT Vatican
WA  NAM Namibia
WI  ESH  Western Sahara
WS  WSM Samoa
WZ  SWZ  Swaziland
YE  YEM  Yemen
YO  n/a Yougoslavia (obsolete 1993)
YU  SCG Serbia and Montenegro
ZA  ZMB  Zambia
ZI  ZWE  Zimbabwe

Sources

• NATO STANAG 1059 (Ed. 7, 2000 and Ed. 8, 2003) Distinguishing Letters for Geographical Entities for Use in NATO