Pakistan on Sunday angrily rejected a media report that raised fears of a militant takeover of the Taliban-hit nation's nuclear weapons and suggested that the US had a hand in protecting the arsenal.
In the latest issue of The New Yorker magazine, investigative journalist Seymour Hersh wrote that US officials had negotiated pacts with Pakistan to provide security for the nuclear arsenal in extreme circumstances.
It also raised the possibility that the threat to the security of the nuclear programme might come not from Taliban rebels battling the government, but from a "mutiny" by fundamentalist elements within the powerful military.
In response, Pakistan's Ministry of Foreign Affairs issued a statement saying that the nation's nuclear materials "are completely safe and secure.
"Pakistan therefore does not require any foreign assistance in this regard," the statement said.
"Nor will Pakistan, as a sovereign state, ever allow any country to have direct or indirect access to its nuclear and strategic facilities. Any suggestion to this effect is simply preposterous."
Pakistan's government is fiercely protective and proud of its nuclear weapons programme, seen as a much-needed deterrent and defence against its arch-foe India, which also has nuclear capabilities.
But soaring attacks by Taliban insurgents -- who struck at the heart of the military establishment in a raid and hostage drama at army headquarters last month -- have raised jitters over the weapons' safety.
Hersh wrote in the The New Yorker that officials in Washington and Islamabad told him that agreements would allow specially trained American units to provide added security for the Pakistani arsenal in case of a crisis.
It also quoted unnamed Pakistan officials as expressing fear that the governments of either Pakistan's ally the United States or their arch-rival India might try to take control of the weapons -- a claim denied by the US.
In response, Larry Schwartz, a spokesman at the US embassy in Islamabad, told AFP that "the United States has no intention to seize Pakistani nuclear weapons or material.
"Pakistan is a key ally in our common effort to fight violent extremists and foster regional security."
The United States is regarded with deep suspicion in Pakistan, with missile strikes by unmanned US drone aircraft against Taliban and Al-Qaeda targets in the northwest tribal belt seen as an infringement of Pakistan's sovereignty.