The Oman newspaper said the two ministers discussed ways of boosting trade and cooperating on the exploration of mineral resources.
Rahmani arrived in the Omani capital for a series of high-profile meetings. Iran’s ISNA state news agency said the visit aimed to prepare for this October’s joint economic commission.
US President Donald Trump said Wednesday that sanctions on Iran would be increased "substantially" soon. His administration has been building an alliance in the Persian Gulf with the stated goal of securing shipping lanes.
Oman has remained neutral as tensions between the two world powers escalated last year. It has stepped in to mediate between Iran and its Arab neighbours as well as the United States.