By Seema Sirohi in Washington
India and the United States have made a historic breakthrough in their relations, striking a deal on civilian nuclear co-operation.
Dr Singh (left) and President Bush
The deal recognises India as a responsible nuclear power entitled to benefits and gains denied for three decades.
The announcement amounts to a huge policy change by the Bush administration which is likely to signal to other nuclear powers that India's situation and position is unique.
It is both a moral and a substantive victory for India which has argued for years against the discriminatory nature of the nuclear world order and insisted on maintaining its nuclear weapons status.
The unprecedented agreement came after President George W Bush and Prime Minister Manmohan Singh met at the White House on Monday.
The two leaders carried forward their determination to be global partners in a wide and varied agenda that stretches from fighting terrorism and proliferation on the one hand and promoting democracy and peace on the other.
India's Foreign Secretary Shyam Saran described the outcome as one that "exceeded expectations".
The agreement would allow nuclear fuel for India's Tarapur reactor. The US helped build the reactor but later reneged on contractual obligations to supply fuel for it because India refused to sign the Nuclear Non-Proliferation Treaty.
Officials said that President Bush's personal commitment and intervention was crucial in pushing the US bureaucracy to set aside their entrenched positions and look at India with new eyes because of the changing global environment.
Apart from the nuclear bargain, India and the US unleashed a series of new initiatives which showcase the broad nature of the new relationship.
As undersecretary of state Nicholas Burns said: "What we've done is to develop with the Indian government a broad, global partnership of the likes that we've not seen with India since India's founding in 1947.
"This has consequences for American interests in South Asia, but also has larger consequences for what we are trying to do globally, in terms of promoting democracy, fighting terrorism, fighting HIV/Aids - and all of those issues were discussed by the two leaders."
The two leaders agreed a series of new initiatives
The official enthusiasm is matched by the show the Americans put on for their new love - India.
A grand welcome ceremony at the White House with full honours, a banquet - only the fifth in as many years of the Bush presidency - and complete and total attention to showcasing the new relationship.
India's ambassador to the US, Ranendra Sen, a great champion of better relations, has worked behind the scene to bring new ideas and initiatives to the table as has the US ambassador to India, David Mulford.
A new forum of chief executive officers was announced where 10 top brains from both India and the US will sit together and think of ways to energise the economic relationship.
At least 10 new initiatives were launched, ranging from ways to spread education in rural India to improving agriculture through linking research organisations of the two countries.
But the nuclear deal was the highlight of the visit.
The deal recognises India's unique position as a nuclear state with rights and benefits which is outside the club of the five permanent nuclear powers.
It is expected to lead to changes in the global nuclear order and accommodation of India.
President Bush agreed to "work to achieve full civil nuclear energy co-operation with India" and work with the US Congress to "adjust US laws and policies" and work with other nuclear powers to change "the international regimes" to allow this new path to be charted.
He made a commitment to invite India to participate in international nuclear research, something that India has demanded for years.
Condoleezza Rice is credited with improving the relationship with India
In exchange India will ensure that its military and civilian nuclear programmes are separate, place its civilian reactors under international safeguards of the International Atomic Energy Agency and continue India's moratorium on nuclear testing
It will also maintain strict controls on all nuclear technology and observe guidelines of the Missile Technology Control Regime and other guidelines observed by nuclear powers.
The agreement shows the seriousness of the Bush Administration's commitment to not just improving but "transforming" relations with India, the emerging global power on the world scene.
Keeping a keen eye on today's geo-politics, the US is strengthening relations with key countries in Asia to counter the rise of China.
While China is never publicly mentioned, it is often the underlying subtext and the reason for the Bush administration.
But it is President Bush himself, and his key advisers such as Secretary of State Condoleezza Rice, who began the second term with a determination to cut through the fog of suspicion, old habits, older policies and defeat the powerful non-proliferation lobby in Washington which has long opposed any accommodation of India in this area.
India is nuclear weapons-capable, as is its main rival, Pakistan
The nuclear deal was not an easy one to strike and negotiations went on until the very last minute.
But in the end a smiling Dr Singh was able to say at a joint press conference with President Bush that the nuclear issue had been resolved to his "great satisfaction".