An Iraqi source told Iranian state media the threat from the Islamic State is causing delays in receiving natural gas from across the border.

Hamid Reza Araqi told the semiofficial Fars News Agency natural gas deliveries should rise once four new phases of the South Pars natural gas field in the Persian Gulf come on stream through 2017.

"Right now we only have a contract to supply Baghdad," he said in an interview published Tuesday. "We will be ready to export gas if they can be ready to receive it from us."

A 60-mile pipeline crossing the Iranian border into Iraq was completed in August. It's designed to export 176 million cubic feet of natural gas per day from South Pars. Iraq, for its part, has struggled to ensure around-the-clock electricity despite its vast natural resource wealth.

A source from Iraq told Fars power plants should've received full supplies of Iranian gas by now, but terrorist threats were inhibiting progress.

"We will be able to receive Iran's gas more safely due to the efforts of the (Iraqi) armed forces to get rid of the Islamic State," he said.

The band of support for IS extends from Aleppo in western Syria to parts of Diyala province in eastern Iraq, which shares a border with Iran.