Some 10,000 soldiers have been deployed to secure the U.S.-ally's nuclear facilities as part of a command and control system headed by President Pervez Musharraf and other top officials, said Khalid Kidwai, head of the Strategic Plans Division which handles Pakistan's nuclear arsenal.
"There's no conceivable scenario, political or violent, in which Pakistan will fall to extremists of the al-Qaida or Taliban type," the retired general said at a briefing for foreign journalists. "Pakistan's nuclear weapons, fissile material and infrastructure are absolutely safe and secure."
Kidwai said his division still planned for any contingency and has reassessed the militant threat in light of escalating attacks on security forces and intelligence personnel, although it had received no intelligence of a terrorist plot against the nuclear facilities.
"You are always responding to threats, the last six months is no exception," he said. "The state of alertness has gone up."
Pakistan, which acquired its nuclear technology secretly and outside international oversight, tested its atom bomb in 1998 in response to a test by its historical rival and neighbor, India.
Fears over the security of its nuclear assets grew after the chief scientist behind its uranium enrichment program, A. Q. Khan, was exposed in early 2004 as having sold sensitive technology to Iran, North Korea and Libya. Pakistan has since instituted its command and control system to prevent a repeat.
But the upsurge in militant violence and U.S. concerns that al-Qaida has regrouped along Pakistan's volatile border with Afghanistan have reignited international concerns. Media reports have said the Pentagon has contingency plans for seizing Pakistan's nuclear facilities if they ever fall into the hands of Islamic extremists.
Kidwai described that as "irresponsible talk" and said the United States would not be able to succeed in such an operation.
The wide-ranging media briefing covered the safeguards Pakistan has put in place to prevent accidental use of a bomb and nuclear proliferation, and even an overview of the procedure for launching a nuclear strike. Foreign diplomats received a similar briefing earlier this month.
Kidwai said that after the Sept. 11 attacks, the U.S. had offered to share its "best practices" in nuclear security, and as a result, Pakistan had accepted $8-10 million dollars in U.S. aid to enhance physical security of its nuclear assets and for training.