The Los Alamos National Laboratory in New Mexico will be closed Monday as fire crews battle a wildfire raging nearby, a statement on the facility's website said.

"All laboratory facilities will be closed for all activities and nonessential employees are directed to remain off site," the statement said. "Employees are considered nonessential and should not report to work unless specifically directed by their line managers."

A spokesman for the New Mexico State Forestry Division, however, told CNN the order to evacuate Los Alamos was voluntary, and stressed that there is no immediate threat to the facility.

The Los Conchas fire, which flared up Sunday afternoon, was reported to be less than a mile from the lab's southwestern boundaries late Sunday, another statement from the facility said.

The fire has spread across nearly 44,000 acres, according to state officials. Approximately 100 local residents have been evacuated, and nearby Bandelier National Monument has been closed for at least three days, they said.

Special crews have been dispatched to Water Canyon near the lab to protect the facility, according to the statement.

"All radioactive and hazardous material is appropriately accounted for and protected," the lab said.

Los Alamos, a center of American nuclear science, is one of the nation's top national-security research facilities.

It "enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns," its website says.

The lab is located about 35 miles northwest of Santa Fe, New Mexico, on 36 square miles of property owned by the Department of Energy. More than 11,000 employees work at the facility.

It is a joint project of Bechtel National, the University of California, The Babcock & Wilcox Company, and the Washington Division of URS, operated for the Department of Energy's National Nuclear Security Administration.