A fast-spreading Alaska wildfire has destroyed up to 45 homes and forced authorities to restrict traffic on a major highway connecting two of the state's largest cities, state officials said on Monday (15 June).

Alaska governor Bill Walker, along with members of the Alaska Forestry Division, addressed public concerns during a press conference on Monday afternoon.

"This morning I received this request of declaration of disaster from Mr Moosey on behalf of the Mat-Su [Matanuska-Susitna] borough. I met with the mayor this morning and we had a briefing before I went out to look at the fire. It is significant. What's really significant is the effort of the firefighters to do what they can to protect the structures that are there," said Walker.

"It was amazing to see the number of homes that were only there because people risked their lives to fight for those homes. The fire itself is very powerful but the human response has been equally powerful. To fly over and see what's been burnt and what's been left, we are so sorry about the losses of structures that have taken place. I'm very pleased there has been no loss of life, I know we've lost some animals in the process and that's most unfortunate."

As many as 200 firefighters have been battling the 6,500-acre fire with more specially trained teams en route from the Lower 48 states, according to the Alaska Forestry Division.

Crews have been attacking the fire on the ground and by air, getting help from the three Alaska National Guard Blackhawk helicopters, according to state reports.

According to the Forestry Division, the fire was ignited by human activity but the specific cause remains under investigation. Dry and warm weather accelerated the blaze.

"Today's fire weather is predicted to be hotter, drier and windier than it was yesterday. So that's our major concern, that we're fighting a large fire with poor fire behaviour conditions. The location of the fire is also very concerning because now it's into Willow proper and so we've got multiple residence, multiple businesses, infrastructure as well.

"Yesterday we had relatively a smaller population and a smaller building footprint and now as we get closer to Willow proper and close into Nancy Lake where there's more homes and more people so you have more structures [...] we're trying to stop it before it gets there but a lot depends on the fire behaviour and the weather," said Casey Cook, Matanuska-Susitna Borough emergency manager.

The fire started early on Sunday afternoon near Willow, about 40 miles north of Anchorage and where the Iditarod, Alaska's famed sled-dog race, typically kicks off.

It initially covered about two acres, but within 11 hours had ballooned to 6,500 acres, according to the forestry division reports. Flames quickly jumped from one 30-40ft spruce tree to the next, forcing a temporary closure of the Parks Highway, which links Anchorage in the state's south central region to Fairbanks in Alaska's eastern interior.

Residents along a 14-mile stretch have been evacuated. By Monday morning, portions of the road re-opened to single-lane traffic. As of Monday morning, about 25 primary homes had been destroyed and as many as 20 secondary residences were also lost.

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