Tehran has expressed concern over delay in starting the Iran-Pakistan gas pipeline.
Iran has also pressed Pakistan to swiftly nominate entities for going ahead with the project.
According to the Express Tribune, sources said Iranian Deputy Minister of Petroleum in International and Commercial Affairs A. Khaledi, in a letter on May 27, reminded Pakistan Government that a government-to-government cooperation agreement has been signed between the two countries.
The minister said the under the agreement, they were supposed to select entities to commence work on the gas pipeline immediately.
Khaledi said Iran has already done this, but it is still waiting for any action from Pakistan side.
Sources said a Pakistan team was also scheduled to visit Iran on June 3 to finalise give the contract to Iranian firm Tadbir Energy that will lay Pakistan's part of the pipeline, but it put off the trip because of transition of power to a new government after general elections, the report added.
Following the agreement between the two sides in the second week of March, Pakistan has failed to pick a sub-contractor for laying the pipeline, which will bring gas from Iran, the report added.