Aliakbar Salehi told told Entekhab news outlet such a war will have unknown dangerous consequences.
The former Iranian foreign minister however said chances of a conflict between Iran and the US are very slim.
Salehi also said the Persian Gulf Arab countries do not want such a military confrontation, although they would like Iran to be contained in their political assessments.
In other comments Salehi added that should a war begin, China will put an end to the Taiwan issue quickly.
His comments follows remarks by the Qatari foreign minister who has warned against attacking the Bushehr nuclear power plant in southern Iran.
The US and the Zionist regime have openly threatened multiple times to attack Iran over its nuclear program. Iran has warned against such an aggression, saying it will be met with a devastating response.