To mark the 90th anniversary of diplomatic ties between the two countries, Abbas Araghchi spoke on Monday at a gathering on bilateral economic exchanges in Tehran.
He noted that Iran continues to face sanctions from the US, adding that he hopes it would overcome the pressure through its strong ties with Japan.
His comments came as diplomatic coordination was underway to finalize Iranian President Hassan Rouhani's visit to Japan later this week.
Japan was a longtime buyer of Iranian crude oil but stopped purchases to comply with US sanctions, Araghchi told NHK, adding that he hopes that the Japanese government and businesses would resume buying Iranian oil.
Iran has been asking Japan and other countries to resume trade and financial transactions that are currently halted, but the countries are yet to respond to that appeal, as US sanctions remain in place, according to NHK.
MNA/PR