Iranian and Omani officials inked an agreement on maritime demarcation in Muscat on May 26.
The agreement was signed by the visiting Iranian Foreign Minister Mohammad Javad Zarif and the Omani Interior Minister Hamoud Bin Faisal Albusaidi.
According to the agreement, the longest sea border between Iran and Oman was delimited within 450 km, Iran's official IRNA news agency reported.
The two reached the agreement after holding ten rounds of expert and technical talks on the issue.
The delimitation of the border between Tehran and Muscat is the first after Iran's 1979 Islamic Revolution.
Zarif arrived in Muscat this morning to discuss bilateral relations
He is scheduled to depart for Kuwait City in the second leg of his regional tour on May 27.
He is due to discuss bilateral, regional and international issues with top officials of Kuwait during his visit.
Foreign minister will attend the 42nd annual meeting of foreign ministers of member states of Organization of Islamic Cooperation (OIC) in Kuwait City.
Zarif's visit to Oman and Kuwait is in line with the government's policy on expansion of bilateral and regional cooperation in confrontation with violence, extremism and crises in the region.