India, Nov. 5 -- Pakistan has dismissed US President Donald Trump's explosive claim that the country has been secretly conducting nuclear weapons tests, saying it "was not the first to carry out nuclear tests and will not be the first to resume them."

A senior Pakistani security official told CBS News that Islamabad maintains a "unilateral moratorium" on testing and remains committed to restraint, even though it is not a signatory to the Comprehensive Test Ban Treaty (CTBT).

"Pakistan was not the first to carry out nuclear tests and will not be the first to resume nuclear tests," the official said in response to Trump's comments during an interview on 60 Minutes.

During the broadcast, Trump alleged that several nations - including Russ...