Iran and Pakistan signed off Tuesday on a project to move gas from the South Pars gas complex in the Persian Gulf to energy-starved Pakistan.
Pakistan gets roughly 50 percent of its energy from natural gas, though domestic capacity is on the decline. Pakistan is faced with power shortfalls, creating rolling blackouts in parts of the country.
India was considered for the project, though a civilian nuclear energy deal reached with Washington in 2008 caused New Delhi to drag its feet on the pipeline.
Washington tried to persuade Pakistan to embrace a rival project from Turkmenistan but instability along the planned route through Afghanistan created complications.
Moeed Yusuf, a South Asia expert for the congressionally funded U.S. Institute of Peace, told The Wall Street Journal that Tuesday's signing was not what Washington had hoped for.
"They don't want Iran getting this opening," he said. "But at this point they're not in a position to offer anything that will stop Pakistan."
Pakistan, under the terms of the Tuesday deal, gets around 750 million cubic feet of natural gas per day from Iran for the next 25 years.