The tourist, identified by cronica.com as a 31-year-old, was walking with an Australian woman and a French man when he was attacked, sources with the Ministry of Security of Mendoza said.
The incident happened at 3.40pm on Monday (1.40am today NZT), cronica.com reported.
Two men on motorcycles attempted to grab a bag when there was a struggle and the New Zealander was shot twice, police director, Juan Carlos Caleri told reporters.
The pair on the motorbikes escaped.
Emergency services found the man dead at the scene, cronica.com quoted Mr Caleri as saying.
A scene examination was carried out and the complex crimes prosecutor, James Garay, questioned witnesses.
The victim and his companions were staying at the Itaka Hostel in Mendoza.
Receptionist Emelio Montalbini told APNZ they had been staying there for about three days.
The Australian and Frenchman were back at the hostel and were distraught, he said.
It was not known if the dead man's family would travel to Argentina.
Mr Montalbini confirmed that police had said the group was targeted by two men on motorbikes who were trying to grab a bag.
"He fall and they shot him.''
It was a "strange'' thing to happen, as the area was normally very safe, Mr Montalbini said.
The incident happened about 2km from the hostel.
Mr Montalbini said he worked nights, but had seen the victim once, and had spoken with him for a few minutes.
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