The Calf Canyon has destroyed hundreds of properties, triggered thousands of evacuations and on Saturday burned within a few kilometres of the city of Las Vegas.

Fueled by ferocious spring winds in parched mountain forests, the fire is by far the largest and most destructive currently burning in the United States.
Fueled by ferocious spring winds in parched mountain forests, the fire is by far the largest and most destructive currently burning in the United States. (AP)

A drought-driven wildfire in northern New Mexico has exploded into a "megafire" of 406 square kilometres and could still more than double in size, a fire official said.

"It's already 100,000 acres. It could easily double in size, maybe even bigger than that," Incident Commander Carl Schwope, told a briefing on Saturday. 

Fueled by ferocious spring winds in parched mountain forests, the Calf Canyon fire is by far the largest and most destructive currently burning in the United States. 

Around 48 km east of Santa Fe, the fire has destroyed hundreds of properties, triggered thousands of evacuations and on Saturday burned within a few kilometres of the city of Las Vegas, New Mexico, population 14,000. 

READ MORE: Largest US wildfire rages close to mountain villages in New Mexico

The blaze grew about 50 percent in 24 hours as a giant column of flame collapsed on Friday night, raining embers and starting new fires. Residents of Las Vegas awoke to pieces of charred wood the size of a US quarter coins carpeting the city. 

Officials feared another "column collapse" at any time.

READ MORE: New Mexico villages evacuate as fires burn uncontrolled in US southwest

'It's all around us'

"It's a big fire and it's all around us," San Miguel County Manager Joy Ansley said by phone, adding that authorities were making plans in case Las Vegas was told to evacuate. 

Firefighters believe the US West faces a grim fire year, with US Department of Agriculture data showing 80 percent of the area in severe drought. 

Under the scenario of a two-degrees-Celsius rise in global temperatures, scientists expect US West wildfires to burn twice the area they do now by as early as mid-century. 

Over a third of the 2,800 firefighters now deployed in the United States were on the Calf Canyon fire, bulldozing firebreaks to defend Las Vegas and fighting ember-sparked "spot fires" creeping towards villages in the Mora Valley. 

So far this year US wildfires have burned more than twice the area than in the same period of 2021 and about 70 percent more than the 10-year average, according to the National Interagency Fire Center.