From the ashes of a mobile home and RV park, US President Donald Trump said he had to come to the heart of California’s killer wildfire to fully grasp the scale of the desolation wrought on the landscape.

“We’re going to have to work quickly … hopefully this is going to be the last of these because this was a really, really bad one,” the president said on Saturday.

He pledged improved forest management practices would diminish future risks.

“I think everybody’s seen the light and I don’t think we’ll have this again to this extent,” Mr Trump said in Paradise, the town largely destroyed by a wildfire ignited on November 8 that he called “this monster”.

At least 71 people have died across northern California 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.

“It’s going to work out well but right now we want to take care of the people that are so badly hurt,” Mr Trump said from what remained of the Skyway Villa Mobile Home and RV Park.

Trump California Wildfires President Donald Trump talks to Mayor Jody Jones as he visits a neighbourhood in Paradise impacted by the wildfires (Evan Vucci/AP)

He noted “there are areas you can’t even get to them yet” and the sheer number of people unaccounted for.

“I think people have to see this really to understand it,” Mr Trump said.

Several burned-out cars were nearby. Trees were burned, their leaves gone. Homes were totally gone, some foundations and twisted steel remained, as did a chimney.

The fire was reported to have moved through the area at 80mph.

Trump California Wildfires Mr Trump gets a briefing from first responders and local officials at an operations centre responding to the wildfires (Evan Vucci/AP)

The president later toured an operation centre, met response commanders and praised the work of firefighters, law enforcement and representatives of the Federal Emergency Management Agency.

“We’ve never seen anything like this in California,” Mr Trump said.

The president took a helicopter tour en route to Chico before he toured Paradise.

A full cover of haze and the smell of smoke greeted the president upon his arrival at Beale Air Force Base near Sacramento, where he was met by Governor Jerry Brown and Governor-elect Gavin Newsom, both Democrats.

Trump California Wildfires The president surveys the scene (Evan Vucci/AP)

Trump left Washington early on Saturday and did not expect to return to the White House until well past midnight.

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

A gunman killed a dozen people at the Borderline Bar & Grill in Thousand Oaks, north of Los Angeles, on November 7 before taking his own life.

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.”