Three Agosta 90Bs were ordered by the Pakistan Navy in September 1994 Each Agosta 90B is able to carry sixteen Harpoon Stand-Off Land Attack cruise missiles. According to the Pakistani Navy Captain Iftikhar Riaz Qureshi, who commanded both of these subs in their test phases, Pakistan purchased its Agosta 90Bs to provide itself with "second strike nuclear capability." Qureshi's words imply that from day one, Pakistan's intention has been to tip these missiles with atomic warheads. And guess what? Since Pakistan tested its first nuclear bomb in 1998, every nuclear device it's made has been a missile warhead.
According to Defence Journal, Pakistan's subs have a range of close to twelve thousand miles…they can travel to the Hudson River or the Chesapeake Bay, unleash their missiles on New York and Washington, then still be able to take refuge in mid-ocean, lay low and threaten other world capitals with a similar fate.
"Any sub equipped with nuclear weapons, is a nuclear sub."
No, you have a different definition then most people.
The Agosta 90B's are Deisel-Electric Submarines.
The US Navy's Submarine force is I believe completely Nuclear driven today (with the exception of some research or possibly rescue type subs).
Calling a submarine Nuclear sub because it can "possibly" carry nuclear weapons is wrong.
By your definition every submarine in the ocean that is in any countries Navy's are nuclear because they can "possibly carry a weapon that can have a nuclear charge. Or by that matter they could just carry a nuclear weapon aboard the sub and become the delivery device.
The classification of a Nuclear sub is given to a submarine that gets its propulsion power from a nuclear power plant.
The Classification of a submarine of diesel-electric means that the submarine gets its propulsion power from a diesel and charges its batteries (electric) prior to submerging or during snorkeling operations. Once the submarine is below periscope depth the submarines propulsion is strictly from the stored energy in the batteries which don't last that long (hours) and have to be recharged. The running of that Diesel engine and the ability to get fuel limit the operational range of this type of submarine.