The White House said yesterday it believed the nuclear weapons laboratory at Los Alamos was safe from the raging fire that has forced the evacuation of 11,000 residents from the New Mexico town.
"Our understanding from the people at Los Alamos is that those assets are protected now," the White House spokesman, Mr Joe Lockhart, said. "The plant is safeguarded and fire resistant - the main assets of that - and I expect that they will be protected."
Flying embers set off spot fires on Wednesday on the grounds of Los Alamos National Laboratory, the largest US nuclear weapons laboratory set up in the 1940s to house the Manhattan Project that created the first atomic bomb in 1945. One blaze swept around a concrete weapons-testing building before it was extinguished.
Officials at Los Alamos said plutonium and high explosives were securely sealed in disaster-proof concrete and steel bunkers.
President Clinton declared the mountainous region of northern New Mexico a federal disaster area on Wednesday.
The fire, started a week ago by National Park Service brush-burning that got out of control, forced Los Alamos's 11,000 residents to evacuate on Wednesday hours before flames started consuming houses.
Mr Lockhart said the US government would do everything possible to contain the fire, which damaged or destroyed two-thirds of the houses in the town.
Mr Clinton offered his sympathies to the people forced to evacuate by what he called the "terrible fire" that had surrounded and engulfed part of the town. "Most important, I just want to give my sympathies to the people who have lost their homes," Mr Clinton said. "This is a very, very difficult situation, and I know that the prayers and support of all Americans will be with the people out there."