WASHINGTON  - The United States said Thursday it was confident of the safety of Pakistan’s nuclear arsenal after heavily armed militants stormed an air force base in clashes that left 10 people dead.

State Department spokeswoman Victoria Nuland offered condolences over the attack claimed by the Taliban. She said the United States had no reason to doubt Pakistan’s account that the Minhas base was free of nuclear weapons.

“We have confidence that the government of Pakistan is well aware of the range of potential threats to its nuclear arsenal and has secured its nuclear arsenal accordingly,” Nuland told reporters. “We do talk about these issues and support Pakistani efforts to keep them secure - we have for quite a long, long time. And we don’t have any reason to be concerned at this moment,” she said.

The assault came as the United States and Pakistan take steps to enhance cooperation, which has been severely strained in recent months over incidents including the US raid that killed Osama bin Laden.

“Pakistanis have suffered more than their share at the hands of terrorists inside Pakistan, which speaks to our efforts to address this threat together,” Nuland said.

Talking to reporters, Pentagon Press Secretary George Little said “I do not have any indication that this particular attack (Kamra) has endangered the Pakistani nuclear stockpile.”

“As for the safety of the Pakistani nuclear programme, we obviously work closely and on regular basis with Pakistani counterparts towards the safety of their nuclear programme. It is our sense that the Pakistani government maintains good security around their nuclear arsenal,” Little said.

Early this week, US Defense Secretary Leon Panetta had expressed concern that Pakistan’s nuclear weapons might land in the hands of terrorist outfits if terrorism inside the country is not brought under control.