The US is worried about the fate of Pakistan's nuclear weapons if President Pervez Musharraf is killed or overthrown while it feels the General may still impose a state of emergency despite ruling it out a couple of days ago, a media report said in New York on Saturday.
American military intelligence officials, it said, are urgently assessing how secure the Pakistani nuclear weapons would be in that scenario - if Musharraf is killed or overthrown.
Quoting three American sources, CNN reported that key questions in the assessment include who would control Pakistan's nuclear weapons after a shift in power.
It said that the three sources independently confirmed details of the intelligence review but would not allow their names to be used because of the sensitivity of the matter.
The United States is pressuring Musharraf, who came to power in a 1999 military coup, not to declare a state of emergency as he faces growing political opposition.
Although the Pakistani government ruled out the declaration of emergency on Thursday, the three sources told CNN the US thinks Musharraf may still impose those measures.
American analysts, the report said, are watching current Pakistani troop movements closely to see whether Musharraf is making any moves that could indicate he is about to impose emergency.
It appears that in recent weeks a large number of troops headed to the Pakistani tribal regions along the Afghan border, officials say.
Stating that the sources include military officers and intelligence community analysts, CNN said the assessment is part of a broader review of the military and security situation in Pakistan.