The agreement passed by the US Congress Saturday allows the export of nuclear fuel and technology to India for the first time in more than 30 years for testing a nuclear device in 1974.
"This nuclear understanding with the USA is significant from the larger perspective of our energy security," India's Foreign Minister Pranab Mukherjee told parliament.
"Energy has become a critical constraint to expanding our economic growth and development," Mukherjee said.
India's main opposition Bharatiya Janata Party and the government's communist allies have criticised the agreement over fears it would impose conditions on India.
Under the accord announced by Indian Prime Minister Manmohan Singh and US President George W. Bush in July 2005, India -- a non-signatory to the nuclear Non-Proliferation Treaty (NPT) -- agreed to place its civilian-use nuclear reactors under scrutiny.
The agreement includes a set of international safeguards to be approved by the International Atomic Energy Agency (IAEA), the global nuclear watchdog, and to which India must adhere.
The law also asks for India's participation in US efforts to "dissuade, isolate, and, if necessary, sanction and contain Iran".
Mukherjee said India would not allow interference in its strategic programme or in foreign policy.
"The government has taken note of certain extraneous and prescriptive provisions in the legislation," he said.
"We have always maintained that the conduct of foreign policy determined solely by our national interests is our sovereign right."
"We have also been clear that our strategic programme remains outside the purview of these discussions. We will not allow external scrutiny of or interference with the strategic programme."
Critics say there are still question marks over the reliability of fuel supplies for civilian reactors.
The deal still needs the endorsement of the influential 45-nation Nuclear Suppliers Group (NSG).
The Indian media welcomed the deal over the weekend, saying it will strengthen ties between New Delhi and Washington.