NEW DELHI: The US administration in 1982 was deeply concerned over Pakistan 's clandestine nuclear programme and possibility of it leaking nuclear components to other countries but President Zia-ul-Haq dismissed such apprehension and conveyed that India was behind such "insidious" campaign to defame Islamabad, as per declassified CIA documents.In a letter to the then President Ronald Reagan, Zia said Pakistan neither possesses nor has transmitted any designs or specifications of nuclear components to anyone and that it is unthinkable for the country to become instrumental in the spread of atomic weapons.He also assured the American President that Islamabad would not build a nuclear bomb, asserting its atomic programme was for peaceful purpose.In the confidential letter dated July 5, 1982, recently declassified by the CIA, Zia had made a veiled reference to India and said there were "open and insidious" attempts to weaken Pakistan's ties with the US and that the peaceful nuclear programme has been misrepresented to divert attention from critical developments in the region.Zia also took strong objection to assertion by the then US Envoy Vernon Walters that there were "incontrovertible" information that Pakistan was planning to acquire nuclear weapons."It caused me deep anguish to have Ambassador Waters speak of incontrovertible information that Pakistan had taken steps to acquire nuclear weapons which threatened seriously to damage relations between the US and Pakistan," Zia said in the letter.In 2015, former Iranian President Akbar Hashemi Rafsanjani had revealed that Pakistan played a key role in the development of Iran's nuclear programme during the 1980s.In clear reference to India, Zia said Pakistan's nuclear programme had been "misrepresented" to such an extent to divert attention from the "critical developments" in the region."We attach equal importance to our new relationship with your great country, and feel confident that it will prove to be enduring. It will be so, if we are conscious of the assaults on this relationship, both open and insidious, by those whose interests are not served by it and if we are determined to defeat them," he said in the letter.Zia said matters of common concerns including "susceptibilities of our Indian neighbour" were addressed.