The move would be a major boost to the nation's energy security, a spokesman for the Ministry of Petroleum and Natural Gas said. TAP would become TAPI after India joins the project.

The Asian Development Bank has backed the project, which is aimed at importing natural gas from the Central Asian nation to meet India's growing energy requirements.

The ADB has called for a meeting of the steering committee of the project between Nov. 28 and 29 in Islamabad, Pakistan, in which India formally would become a partner in the project. Following India's formal induction, the four member nations are expected to sign a Project Heads of Agreement and a Gas Pipeline Framework Agreement.

Until now, India had observer status in the project.

The spokesman said the proposed pipeline would have a capacity of 33 billion cubic meters per year. The $4 billion, 1,680-kilometer pipeline will run from the Daulatabad gas field to Afghanistan. From there it will be constructed from Herat to Kandahar, and then via Quetta and Multan in Pakistan.

The pipeline faces logistical roadblocks, however, as it runs through Afghanistan and Pakistan, where security is likely to be a major concern.