Iran says a deal between Saudi Arabia and Kuwait to develop the Arash/Durra joint offshore gas field is “illegal” because Tehran is not included in the project.

Foreign Ministry Spokesman Saeed Khatibzadeh said on Saturday that Iran has a share in the field and must be included in any action to operate and develop the field.

Khatibzadeh said, "The Arash/Al-Durra gas field is a joint field between Iran, Kuwait and Saudi Arabia. Parts of it are located in areas between Iran and Kuwait whose water boundaries have not been defined. The Islamic Republic of Iran also reserves the right to exploit the gas field".

He added, "The recent move by Kuwait and Saudi Arabia in the framework of a cooperation document is contrary to what has been previously negotiated and is illegal. It has no effect on the legal status of the field and is not approved by the Islamic Republic of Iran. In accordance with international regulations and procedures, any action in the operation and development of this field must be in coordination with all three countries”.

Kuwait Petroleum Corporation announced the signing of the contract between Saudi Arabia's energy minister and his Kuwaiti counterpart in a statement on Monday.

According to the contract, the joint gas field -- called Arash in Iran and Durra by the Arab countries -- is expected to produce one billion standard cubic feet per day of gas and 84,000 barrels per day of condensates.

The offshore field was discovered in 1967 and is estimated to have a total proven reserves of around 20 trillion cubic feet of gas.