"At this time, as far as I know, it is the assessment of the intelligence community that Pakistan's weapons arsenal is secure," spokesman Scott Stanzel told reporters near the president's ranch in Crawford, Texas.

Stanzel did not say whether President George W. Bush, who is spending the remainder of the year at his Texas home, brought up the nuclear question during a phone call to Pakistan President Pervez Musharraf yesterday.

But he acknowledged that it was a major topic of discussion between US and Pakistani officials amid fears of further instability in the wake of Bhutto's death.

Stanzel said "there have been discussions" with army chief General Ashfaq Kiyani on "what we can do to help on the political and security front, while we're having conversations with people throughout Pakistan."