"Connecting all cities in the southeastern province to the national grid needs at least three years. All households in Zahedan, capital of the province, are expected to be linked to the network by January 2020," Hassan Montazer Torbati was quoted as saying by the Oil Ministry's news portal.
Close to 520 kilometers of high-pressure gas pipes have been laid in Zahedan and more than 26,000 households have been added to the natural gas grid in the city since last year.
According to a 2017 census, Zahedan has a population of more than 650,000 in 130,000 households, Financial Tribune reported.
"As soon as we are done in the capital, the main pipeline that is an extension of the Iran Gas Trunkline 7 (IGAT-7) will be extended to other major cities namely Zabol, Khash, Iranshahr and Chabahar," he said. Until then the homes will get CNG in cylinders.
IGAT-7 stretches over 900km between Asalouyeh, Bushehr Province, and Iranshahr in Sistan-Baluchestan Province.
In implementing the gas delivery plan $450 million has been spent on laying pipes, the official said, and expressed the hope that most cities in the deprived areas will be linked to the national grid by 2021.
CNG is made by compressing natural gas (mainly composed of methane) to less than 1% of the volume it occupies at standard atmospheric pressure.
The official noted that 3,000 small towns and villages are connected to the grid annually and 80% of rural regions now have access to piped gas.
Iran's Natural gas grid has expanded about 390,000 kilometers over the past three decades.