Investigative journalist Seymour Hersh says the US has a rapid response unit ready to secure Pakistan's nuclear weapons in the event of a mutiny or "any nuclear incident", a claim the US and Pakistani governments have denied.

Speaking to Al Jazeera, Hersh discussed his report which appeared in The New Yorker magazine and said a team was scrambled recently to respond to what was thought to be a nuclear emergency in Pakistan, which turned out to be a false alarm.