The government of Turkmenistan signed agreements Wednesday to sell natural gas to its Asian partners through the 1,043-mile pipeline.
Indian Oil Minister S. Jaipal Reddy said signing off on the agreement would lay the groundwork for construction of the project.
The agreement is "a triumph of multilateralism, regional cooperation and economic integration," he was quoted by the Press Trust of India as saying.
India and Pakistan would get about 1.3 billion cubic feet of natural gas from the pipeline each year, while Afghanistan would get the remaining 494 million cubic feet per year, the report stated.
"Without a doubt, the economic benefits of the TAPI gas pipeline will be immense for our energy-starved economies," said Reddy. "The flow of natural gas will bring in industrial and economic development in our countries."
TAPI, supported by the United States and backed by the Asian Development Bank, is seen as a rival to a pipeline planned by Iran. Tehran said much of the pipeline is built through its territory and it was ready to help Pakistan build its part of the project.