Pakistan's prime minister on Monday defended his country as a responsible nuclear power, shooting down concerns at a major security summit that extremists could seize loose weapons.
Prime Minister Yousuf Raza Gilani, who controls the Islamic world's only declared nuclear arsenal, rebuffed calls to halt production of fissile material and insisted that Pakistan needed a deterrent against historic rival India.
Instead, Gilani made a new pitch to the United States - which relies on Pakistan in its campaign against Islamic extremists - to support the blackout-plagued nation in developing civilian nuclear power.
"I assure you that Pakistan, as a responsible nuclear state and an emerging democracy, stands with the international community in its effort to make this world a better place to live in," Gilani told a roundtable with reporters.
Foreign Minister Shah Mehmood Qureshi, who accompanied Gilani, said Pakistan had explained to the United States the three-layer security system it has put in place for its nuclear arsenal.
"We are confident that our system is second to none. It's world class," Qureshi said. "Fortunately there has been no incident."
Abdul Qadeer Khan, the father of Pakistan's nuclear bomb, publicly confessed in 2004 that he shared atomic secrets with Iran, Libya and North Korea, although he later retracted his remarks.
The United States is reported to have quietly set up an elite squad that could fly into Pakistan and attempt to secure its weapons if the government disintegrated.
John Brennan, the top anti-terrorism adviser to President Barack Obama, warned Monday that Al-Qaeda's interest in nuclear weapons was "strong" and said the risk of nuclear terrorism was "real," "serious" and "growing."
A study by Harvard University's Kennedy School of Government said that Pakistan was one of the greatest worries for nuclear safety.
Pakistan's arsenal is heavily guarded, but the report said that the Khan case, pervasive corruption and high-profile attacks against military bases showed the risks.
"While Pakistani generals share the US concern over extremist threats to their nuclear stockpiles, their first concern is protecting these stocks from Indian strikes - or American seizure," said the report led by Harvard professor Matthew Bunn.
Lisa Curtis, an expert on South Asia at the Heritage Foundation, said the best way for the United States to ensure the security of the nuclear arsenal was to develop trust with Pakistan.
"While the probability of Taliban militants over-running the country and gaining control of Pakistan's nuclear arsenal is far-fetched, the real danger lies in potential links between retired officials and nuclear scientists with access to nuclear information to Taliban and Al-Qaeda terrorists," she said.
A Washington research group, the Institute for Science and International Security, last month said satellite imagery showed steam coming from the Khushab site, a sign that Pakistan has started plutonium production from a second reactor.
UN Secretary-General Ban Ki-moon said he would use the two-day Washington summit to press for an international ban on the production of new fissile material for nuclear weapons.
A 65-nation conference in Geneva last year called for a treaty but Pakistan has been the leading opponent, fearing it would alter its strategic balance with India.
India and Pakistan, along with possibly Israel and North Korea, are the only states that continue to produce fissile material for nuclear weapons.
Gilani did not address the fissile material issue directly, saying only that Pakistan has discussed it with the United States.
"For a minimum deterrence, we have to have. That is our requirement," he said of nuclear material.
Gilani renewed calls for the United States to work with Pakistan on a civil nuclear agreement similar to one with India, noting that some Pakistanis spend hours each day without electricity in extremely hot weather.
"Pakistan rightfully expects the US to adopt non-discrimination in terms of a civil nuclear deal with Islamabad," Gilani said.
Cautious not to offend Pakistan, the Obama administration has not ruled out nuclear cooperation. But few US experts predict a deal anytime soon.