NATO-3 Law and Legal Definition
A NATO-3 visa is a non-immigrant US visa available to official clerical staff accompanying the representative of a NATO member state and the immediate family of NATO-3 visa holders.
‘Immediate relatives’ includes only the spouse of the representative and his unmarried sons and daughters of any age. The application procedures are the same as for the principal applicant.
NATO officials who intend to travel to the US on official business must obtain a "NATO" visa prior to their entry. They cannot travel on tourist visas, or visa free under the Visa Waiver Program.
NATO -3 visa holders are exempt from entry into the US-VISIT program.