India has thermonuclear capabilities, National Security Advisor MK Narayanan has emphasised, saying the scientists who raised doubts about the 1998 nuclear tests in Pokhran had personal motives to do so.
Narayanan spoke to CNBC-TV18'S Karan Thapar in an interview to be broadcast Monday night. He insisted that India had the thermonuclear device - the first time a government official has made this statement publicly after the recent controversy.
"We have thermonuclear capabilities. I am absolutely sure. Even if we are hit, we will have enough to be able to deliver something," said Narayanan.
Former senior DRDO official K Santhanam had raised doubts that India's thermonuclear test in 1998 had not worked.
"I have chosen my words very carefully - (the yield was) 45 kilotons... And nobody... including Santhanam, who has absolutely no idea what he is talking about... knows, for that matter any one else can contest what is a proven fact by the data which is there," said the NSA.
He said the Atomic Energy Commission had last week given the "most authoritative" statement on the efficacy of the 1998 nuclear tests and no more clarification was required from the government.
Narayanan indicated that the sudden statements by Santhanam and other senior nuclear scientists could be a result of personal rivalries within the scientific community.
He rejected the suggestion that a panel of scientists could review the Pokhran test results, asserting that it would be difficult to get neutral, independent scientists who could investigate the matter.
"Which peer scientists are we going to bring in (for a panel)? All those peer scientists are part of the establishment or are sceptics," he said.
Narayanan said he was aware of reports that Pakistan had increased its nuclear arsenal. He stated that India will suitably respond to do whatever is required in national interest to increase nuclear deterrence.
"The fact that a country not friendly is building up its arsenal is a concern... We will do what we have to do."
He added: "We have absolutely no intention of changing no-first use doctrine. We are committed to (it)."
On Pakistan reportedly diverting US technology and weapons for use against India, Narayanan said India had taken up the matter a number of times with the US but the latter had only responded by offering the same equipment to India.
But he admitted that India was worried about the modification of Harpoon missiles by Pakistan.