Washington is to deploy more personnel and mercenaries in Libya to seek and destroy as many as 20,000 surface-to-air heat-seeking missiles (SAMs) that have gone missing during the Nato-backed insurgency.
White House spokesman Jay Carney said on Tuesday that a State Department official was currently working with Libya's National Transitional Council (NTC) to secure the SAMs, alongside five "contractors" specialising in explosive ordinance disposal.
"We expect to deploy additional personnel to assist the NTC as they expand efforts to secure conventional arms storage sites," Mr Carney said, adding that the US government was co-operating with the NTC through the State Department and in the UN.
Russian-made SAM missiles are portable and light enough to be launched from a fighter's shoulder.
They hone in on the heat generated by aircraft engines and can down planes at a range of over two miles.
The cost of a SAM has dropped dramatically in recent months, apparently because Libyans who looted weapons stores amid the chaos of the uprising and ensuing civil war have flooded the black market with them.
Former White House counterterrorism advisor Richard Clarke said: "I think the probability of al-Qaida being able to smuggle some of the stinger-like missiles out of Libya is pretty high."
Recent Israeli media reports have expressed concern that Palestinian militants in Gaza are working to get their hands on the weapons.