The CASA-1000 power project has been inaugurated by officials from Afghanistan, Pakistan, Tajikistan, and Kyrgyzstan.
The $1.17 billion project was unveiled in a ceremony in Dushanbe on May 12.
Afghan Chief Executive Abdullah Abdullah, Pakistani Prime Minister Nawaz Sharif, Tajik President Emomali Rahmon, and Kyrgyz Prime Minister Sooronbai Jeenbekov attended the opening ceremony.
The CASA-1000 involves building a 1,222-kilometer power-transmission line to carry some 1,300 megawatts of electricity from hydropower plants in Kyrgyzstan and Tajikistan into Afghanistan (300 MW) and on to Peshawar in Pakistan (1,000 MW).
CASA-1000, which faces significant obstacles, is scheduled to be completed by 2018.
The project is being financed by the United States, Britain, the World Bank, European Investment Bank, and the Islamic Development Bank.