President Donald Trump blames poor forest management for deadly fires on the US West Coast which have so far killed at least 33, burned millions of acres and destroyed thousands of homes.
But many of the blazes have roared through coastal scrub and grasslands, not forest.
On a visit to California, Mr Trump was asked if climate change was also part of the problem, in combination with forest management.
“Well, I think something’s possible, I think a lot of things are possible,” Mr Trump said.
“But with regard to the forest, when trees fall down after a short period of time, about 18 months, they become very dry.
“They become really like a matchstick and they get up, you know, there’s no more water pouring through.”
He said downed trees and dried leaves on forest floors eventually “just explode”.
The President said countries in Europe don’t have the same issues with wildfires because they manage their forests.
“So we have to do that in California,” he said.
“I mean, people don’t like to do cuts, but they have to do cuts in between.
“So if you do have a fire and it gets away, you’ll have a 50 yard cut in between.
“So it won’t be able to catch to the other side. They don’t do that. If you go to other countries, you go to Austria, you go to Finland, you go to many different countries and they don’t have fires.”
At a fire briefing, Californian Governor Gavin Newsom said his state can do a better job of forest management.
But he told Trump that it is “self-evident that climate change is real and that is exacerbating this”.
“The ferocity of these fires, the drought, five-plus years, losing 163 million trees to that drought,” Mr Newsom said.
“And so I think there’s an area of at least commonality on vegetation forest management.
“The dries are getting drier. When we’re having heat domes, the likes of which we’ve never seen in our history, the hottest August ever in the history of the state.”
California Natural Resources Agency Secretary Wade Crowfoot, argued: “If we ignore that science and sort of put our heads in the sand and think it’s all about vegetation management, we’re not going to succeed together in protecting California.”
Mr Crowfoot retorted: “I wish science agreed with you.”
Mr Trump got in the last word of the exchange: “Well, I don’t think science knows actually.”
Authorities in Oregon, the state just north of California, said more than 20 people remain missing from the wildfires.
Governor Kate Brown said 10 people are confirmed dead in the state and that number would likely rise.
She said the fires were a wake-up call to the seriousness of climate change.
“This is truly the bellwether for climate change on the West Coast,” Ms Brown said.
“We saw incredible winds. We saw very cold, hot temperatures. And of course, we have a landscape that has seen 30 years of drought.”
The fires have forced tens of thousands to flee and cast a shroud of smoke that has given Seattle, San Francisco and Portland some of the worst air quality in the world.
The California National Guard has airlifted scores of stranded people to safety over the past week.
Mr Trump has authorised federal disaster aid for both states.