US President Donald Trump has taken a helicopter tour over the northern California landscape scorched by a killer wildfire.

A full cover of haze and the smell of smoke greeted the president upon his arrival at an Air Force base, as did the governor and his successor.

Mr Trump planned to hear from those leaders about the dire situation and talk to first responders.

He was later was expected to travel several hundred miles south to visit victims of a recent country music bar shooting.

“Look forward to being with our brave Firefighters, First Responders and @FEMA, along with the many brave People of California. We are with you all the way – God Bless you all!” Mr Trump tweeted while heading west on Air Force One.

Landing at Beale Air Force Base, he was greeted by Governor Jerry Brown and Governor-elect Gavin Newsom, both Democrats. Trump boarded Marine One without making public remarks.

The president, who left Washington early on Saturday and did not expect to return to the White House until well past midnight, planned to get a first-hand look at the devastation from the wildfire that has destroyed the town of Paradise and heavily damaged the outlying community of Magalia.

At least 71 people have died and authorities are trying to locate more than 1,000 people, though not all are believed missing.

More than 5,500 fire personnel were battling the blaze that covered 228 square miles (590 square kilometres) and was about 50% contained, officials said.

Mr Trump also was expected to stop in Southern California, where a gunman killed a dozen people at the Borderline Bar & Grill in Thousand Oaks on November 7 then ended his own life.

California Wildfires
Firefighters search for human remains in a trailer park in Paradise that was destroyed in the wildfires (John Locher/AP)

The president has struggled to convey empathy to victims of national disasters and tragedies.

His first reaction to the fires came in a tweet last week: “There is no reason for these massive, deadly and costly forest fires in California except that forest management is so poor.

“Billions of dollars are given each year, with so many lives lost, all because of gross mismanagement of the forests.”

Nature and humans share blame for the wildfires, but forest management did not play a major role, despite Trump’s claims, fire scientists say.

Trump California Wildfires
Donald Trump greets California Governor-elect Gavin Newsom as Governor Jerry Brown watches on (Evan Vucci/AP)

Mr Trump stuck to the theme in his remarks just before departing on Saturday when he outlined what he planned to discuss with Mr Brown and Mr Newsom.

He said “We will be talking about forest management … The one thing is that everybody now knows that this is what we have to be doing and there’s no question about it.

“It should have been done many years ago but I think everybody’s on the right side.”

Mr Trump, who has long feuded with the political leaders of heavily Democratic California over issues such as immigration and voting, has also threatened to withhold federal payments to the state.

After being criticised for his response, the president has shifted gears, expressing words of encouragement to first responders and those of sympathy for hit victims.

“It seems that many more people are missing than anyone thought even possible,” Mr Trump told reporters in Washington, saying he looked forward to meeting fire responders and firefighters who have been “incredibly brave”.

But when he was asked by Fox News in an interview set to air Sunday whether climate change played a role in the number of serious fires, he said “maybe it contributes a little bit – the big problem we have is management”.

He added he was surprised to see images of firefighters removing dried brush near a fire.

“This should have been all raked out,” he said.

Mr Brown and Mr Newsom said on Friday they welcomed the president’s visit and “now is a time to pull together for the people of California”.