WASHINGTON: A leading American foreign policy journal today alleged that India is building a top-secret nuclear city to produce thermos nuclear weapons which would upgrade the country as a nuclear power and unsettle its two major neighbours - Pakistan and China Foreign Policy magazine alleged that India started building this secret city in Challakere in Karnataka, which when completed in 2017 would be "the subcontinent's largest military-run complex of nuclear centrifuges, atomic-research laboratories, and weapons- and aircraft-testing facilities"."But another, more controversial ambition, according to retired Indian government officials and independent experts in London and Washington, is to give India an extra stockpile of enriched uranium fuel that could be used in new hydrogen bombs, also known as thermonuclear weapons, substantially increasing the explosive force of those in its existing nuclear arsenal," the investigative report said."India's close neighbours, China and Pakistan, would see this move as a provocation: Experts say they might respond by ratcheting up their own nuclear firepower," the report said.The report does not contain any official response from either the Indian or the US government , but has quoted several unnamed officials and retired government officials for the story."Mysore is being constantly monitored, and we are constantly monitoring progress in Challakere," a former White House official has been quoted as saying by the report.