India's top nuclear scientists and Communist parties have welcomed PM Manmohan Singh's assurances on the controversial nuclear deal with the US.
Mr Singh said India would not accept any pressure from the US
Mr Singh said on Thursday that India would not accept any US pressure to cap its atomic weapons programme.
Some in India fear Washington is trying to change the terms of the agreement which was signed last year.
The deal gives India access to civilian nuclear technology in return for having its civilian nuclear sites inspected.
Critics say it will undermine global nuclear security efforts as India has not signed the nuclear Non-Proliferation Treaty (NPT).
In a heated, often emotional, debate in the upper house of parliament on Thursday, Mr Singh strongly defended the nuclear agreement that he signed with President George W Bush.
He said India would not accept any move by Washington that would impede its atomic weapons programme, nor would it allow any international scrutiny of its military facilities.
And Mr Singh also argued that the deal was in India's interests.
The prime minister has invited the country's top scientists for further discussion on the subject next week.
MR Srinivasan, former chairman of India's Atomic Energy Commission (AEC), said scientists were looking forward to the meeting.
"Unless India makes the US explicitly accept the position that the prime minister adopted and unless the bilateral agreement is clearly reflected in black and white, there will be no guarantee that what is deemed non-binding on India in today's legislation will not be converted in future to binding clauses by future administrations in the US," Mr Srinivasan was quoted as saying by the Press Trust of India news agency.
Energy-hungry India needs nuclear power
Former AEC chairman PK Iyengar echoed the same sentiment.
"The prime minister has made so many commitments to answer the scientists as well as opposition's concerns and at the same time he has not left out his commitment related to the American decision," he said.
India's main Communist parties, who are allies of the ruling Congress-led federal government, also said they were satisfied with Mr Singh's assurances.
"The prime minister assured that the government would stick to the stand based on all the doubts raised by us and he even went on say that if there was any pressure on part of the US on these questions or to change the deal, the government would reconsider the bill," Communist Party of India (Marxist) leader Sitaram Yechury said.
Indian newspapers and analysts lauded Mr Singh's performance in parliament.
"The prime minister has finally stood up to defend the constitutional right of his government to conduct foreign policy," analyst CR Raja Mohan wrote in the Indian Express newspaper.
He called Mr Singh's speech "impressive".
"He's gaining in stature and confidence and that's very good news. He's willing to respond to his political opponents in a political manner, no longer only in a defensive or a technocratic manner," Mr Raja Mohan told the AFP news agency.