The confirmation of the International Atomic Energy Agency agreement is meant to promote a major nuclear partnership with the United States, and is a signal newly-elected Prime Minister Narendra Modi seeks stronger U.S. ties.
Modi and U.S. President Barack Obama will meet in September in Washington.
"I can confirm that we are ratifying the Additional Protocol to the IAEA Safeguards Agreement," said Syed Akbaruddin, spokesman for the Ministry of External Affairs, adding it denotes India's pledge of "responsible use of nuclear power."
The agreement is lacking in that India -- which first tested a nuclear bomb in 1974 and was engaged in an arms race with Pakistan, resulting in three wars since 1947 -- could now become a trader in nuclear materials. India is not a signatory to the nuclear Non-Proliferation Treaty, and is not subject to IAEA inspections.
In 2009, the IAEA approved the Additional Protocol, a diplomatic attempt to allow India to trade with members of the Nuclear Suppliers Group, an organization of 48 countries.
Ratification of the agreement is regarded as a gateway to separating India's civilian and military nuclear programs, and could bring India tens of billions of dollars in investments in domestic nuclear generation.