By Ian MacWilliam
BBC Central Asia correspondent
The United States has outlined an ambitious energy project to develop the energy sources of the ex-Soviet republics of Central Asia.
Afghanistan's energy need are growing as it recovers from war
The plan would develop a regional power grid from Kazakhstan to India.
The grid would feed the growing energy needs of India, Pakistan and Afghanistan, and help integrate the economies of Central and South Asia.
The far-reaching plan would also reduce Central Asia's reliance on routes through Russia for its energy exports.
The US Assistant Secretary of State, Richard Boucher, presented the plan to committee in Congress.
He explained how the development of a power grid through Afghanistan would enable the energy-rich nations of Central Asia to sell electricity to energy-poor India and Pakistan.
The impoverished mountainous republics of Kyrgyzstan and Tajikistan both want to develop their large hydro-electricity potential.
Kazakhstan, with abundant oil and gas, is rapidly becoming a top energy producer while Turkmenistan has some of the world's largest gas reserves.
India and Pakistan have both been seeking ways to import Central Asian oil, gas and electricity to fuel their expanding economies.
Even Afghanistan now needs more energy as its war shattered economy begins to recover.
Mr Boucher said the opening up of Afghanistan meant that it should now be seen as a bridge not an obstacle between Central and South Asia.
Historically, Central Asia always had close ties with Afghanistan and India until they were broken by Soviet isolationism imposed by Moscow.
But continuing insecurity in parts of Afghanistan has long prevented the rebuilding of economic ties. Now American officials and other observers say the best way to reintegrate Afghanistan and to improve stability in the entire region is to boost economic integration.
Under President Vladimir Putin, Russia has been increasing its efforts to recover lost economic influence in Central Asia, but US policy has long been to wean the Central Asian republics away from their old reliance on Moscow.