Iranian Ambassador to Afghanistan Mohammad Reza Bahrami said the country's vice president met the victim's family, Khaama press reported.
Bahrami has also promised quick action by the authorities for the trial of the rapist.
A six-year-old Afghan girl was abducted, raped and then murdered by an Iranian teenager. The girl, according to the media, was also burnt with acid to hide the incident.
Iranian police said the authorities have released special orders to follow the case.
The murder of the girl in Veramin city of Iran sparked anger in Afghanistan and elsewhere after reports about the horrific incident emerged. (IANS)