Saudi Arabia and Kuwait are the only states with rights to the natural resources in Al Durra gasfield, the Saudi Foreign Ministry said in a statement.
It said the countries “alone have full sovereign rights to exploit the wealth in that area”.
They also renewed calls for Iran to negotiate the eastern boundary of the area.
Iran previously claimed it had a stake in the field and called the Saudi-Kuwaiti agreement to develop it “illegal”.
Saudi Arabia's statement came after Tehran announced it was ready to explore the field.
Last month, Mohsen Khojasteh-Mehr, managing director of the National Iranian Oil Company, said there was “full preparation to start drilling in the joint Arash oilfield. Considerable resources have been allocated to the implementation of the development plan for this field.”
Kuwaiti Oil Minister Saad Al Barrak has declared his opposition to Iran’s planned activities in the area.
“We categorically and totally reject Iran’s planned activities around the premises of the Al Durra offshore gasfield,” he said.
The Kuwaiti-Saudi joint permanent committee in July said it was monitoring progress on oil projects in the area and intended to eliminate any “impediments”.
Kuwaiti Oil Ministry undersecretary Sheikh Nimr Al Sabah said the committee was working to “develop and exploit” the natural resources “to meet the growth of domestic demand".
This year, Kuwait and Iran held talks in Tehran, discussing the need to resolve the issue in accordance with international law.
Al Durra gasfield is a submerged area between the kingdom's Eastern Province and Kuwait.
The oilfield discovery coincided with the demarcation process for the maritime borders between Saudi Arabia and Kuwait in the 1960s.
Kuwait and Saudi Arabia signed an agreement in 2019 in which oil production was divided in the neutral areas that lie between the countries.
Both countries signed agreements to invest in Al Durra gasfield in 2022.
