Pakistani and Iranian leaders in March met along their shared border for a ceremony to mark the formal construction of a $7.5 billion natural gas pipeline from Iran.
The project has faced a series of delays since it was proposed as the so-called Peace Pipeline in the 1990s. India was included as an early partner but has since stayed on the sidelines in part because of economic pressure from the United States.
Iran and Pakistan in 2011 said they would move ahead on their agreements for the pipeline without India. An official source who spoke to Iran's semiofficial Fars News Agency on condition of anonymity said Pakistan could face penalties if it does not make a formal commitment.
"If Pakistan doesn't revise its behavior on the construction of the peace pipeline, it will be fined based on the bilateral agreement [with Iran]," the source was quoted as saying Saturday.
The pipeline could carry as much as 300 billion cubic feet of natural gas to Pakistan if constructed. The Pakistani government said the pipeline could help tackle an ongoing domestic energy crisis though the Iranian source said frustrations were growing because of the lack of concrete developments.