Air New Zealand will launch a three-times weekly service between Auckland and Buenos Aires in December 2015.
The carrier will operate a Boeing 777-300 aircraft on the route.
It will also enter into a codeshare agreement with Aerolineas Argentinas, subject to regulatory approval, that will see ANZ add its code onto Aerolineas Argentinas' services to Brazil, while Aerolineas Argentinas' code will be added on "key connecting Trans-Tasman services".
ANZ CEO Christopher Luxon said: "We've been very clear about our aspirations for growth in the Pacific Rim. Our flights to Singapore commence next month and this new route to Buenos Aires further strengthens our network in the Pacific Rim.
"Argentina is an exciting new destination for New Zealanders, and with seamless one-stop connectivity through Auckland it will provide a fantastic opportunity for Australians as well."
Tickets for the route go on sale in March.
Earlier this month, ANZ started operating out of Tom Bradley International Terminal at Los Angeles International airport (see news, November 6).