The White House on Thursday said it believed thousands of man portable air defense systems ( MANPADS) have been destroyed in Libya, and the United States is working with the Libyan authorities to secure dangerous materials in Muammar Gaddafi regime's stockpile.

The White House Spokesman Jay Carney made the assessment during his daily briefing with reporters, saying that U.S. teams on the ground have "already disabled or destroyed hundreds of MANPADS in Libya."

"In addition, we believe that thousands of MANPADS were destroyed during NATO operations," said Carney.

In remarks on the death of Gaddafi, U.S. President Barack Obama called on the Libyan authorities to work with international community and "secure dangerous materials."

Carney recounted U.S. effort in helping Libya secure its conventional weapon stockpiles, especially MANPADS, the shoulder- fired anti-aircraft missiles, which could pose a potential threat to civil aviation in the wrong hands.

He said that upon Libyan authorities' requests, the United States has activated 3 million dollars in aid to Mines Advisory Group and the Swiss Foundation for demining, surveying and securing bunkers, clear unexploded ordnance, and destroying unsecured conventional weapons, including MANPADS.

The administration also allocated 2.75 million dollars to fund a quick-reaction force, made up of civilian technical specialists to go into Libya since early Sept. to secure such weapons.

Carney said that the administration is having "ongoing consultations with regional governments and our international partners to build a coordinated approach to this shared security challenge."