Islamabad, Pakistan ? Pakistan’s nuclear weapons are safe from Taliban and al-Qaida militants because of the military’s stringent security system and a political climate that precludes a takeover by religious extremists, a top official said Saturday.

Seeking to dispel international concerns amid increased violence, Khalid Kidwai, leader of the Strategic Plans Division that handles Pakistan’s nuclear arsenal, said Pakistan uses 10,000 soldiers to keep the weapons safe and has received up to $10 million in U.S. assistance to that end.

“There’s no conceivable scenario, political or violent, in which Pakistan will fall to extremists of the al-Qaida or Taliban type,” Kidwai told foreign journalists at a briefing. “Pakistan’s nuclear weapons, fissile material and infrastructure are absolutely safe and secure.”

Kidwai, a retired general, said his division was prepared for any contingency and had reassessed the militant threat in light of escalating attacks on security forces and intelligence personnel. He said he had received no information of a terrorist plot against nuclear facilities.

Pakistan, which acquired its nuclear technology secretly and outside international oversight, tested its atom bomb in 1998 in response to a test by India, its historical rival and neighbor.

Worries over Pakistan’s nuclear security deepened when 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.

Khan, the scientist who became a national hero for his role in developing Pakistan’s atomic bomb, remains under house detention. Pakistan insists the government was unaware of his dealings, but it refuses to allow foreign investigators to question him in person.

Pakistan has since instituted a command and control system to prevent a repeat, but new security questions arise as Taliban fighters expand their reach beyond the Afghan border and al-Qaida reportedly regroups.

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 called it “irresponsible talk” and said the United States would not succeed in such an operation.

Kidwai spoke as residents in northwestern Pakistan fled their homes a day after security forces there began pounding militants’ hideouts, killing 30 suspected militants, officials and residents said Saturday. Authorities blamed the militants for hijacking four truckloads of military supplies earlier this week.

The fighting marked the first time the violence has spread to Dara Adam Khel, a town on a key road linking Peshawar with the battlefields of Waziristan, a lawless region regarded as a stronghold for Taliban and al-Qaida.