Donald Trump is to visit California on Saturday where he will meet people caught up in this month's devastating wildfires, the White House has said.
The US president initially blamed the blazes, which have claimed at least 58 lives, on state officials and threatened to withhold federal payments.
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. Remedy now, or no more Fed payments!
— Donald J. Trump (@realDonaldTrump) November 10, 2018
Mr Trump tweeted last weekend: "There is no reason for these massive, deadly and costly forest fires in California except that forest management is so poor."
The number of dead seems likely to rise, as 300 people are listed as missing.
Rescue workers have been combing through the charred ruins of the town of Paradise a week after it burned to the ground in the Camp Fire in northern California, the worst in the state's history.
Strong winds caused the fires to spread quickly, people could not escape and authorities fear some elderly residents may have been left behind in the panic.
At least 22 cadaver dogs have been helping with the search.
More than 9,000 firefighters from across the country, using more than 1,000 engines, have been battling the blazes, including the Camp Fire and the Woolsey Fire, around 500 miles (805km) to the south.
Nearly 8,700 homes have been destroyed and 15,500 buildings threatened, the California Department of Forestry and Fire Protection (Cal Fire) said on Thursday.
Cal Fire said the Camp Fire had grown to 140,000 acres (57,000 hectares), but was 40% contained.
Two people were killed by the southern California Woolsey Fire and a third death in the area is being investigated to see if it is linked to the blaze.
Mr Trump's interior secretary Ryan Zinke, visiting the area affected by the Woolsey Fire, warned of the risk of mudslides in Los Angeles and Ventura counties in its wake.
More than 200,000 left their homes to escape the blaze, including the entire seaside community of Malibu.
Classes have been cancelled for tens of thousands of university students as smoke drifts south, polluting the air in Sacramento and the San Francisco Bay area.
More from California Wildfires
There has been an outbreak of norovirus at a shelter housing people who left their homes to escape the Camp Fire, according to a Butte County public health spokeswoman.
Meanwhile, a number of celebrities have lost their homes in Malibu as a result of the inferno, including Pierce Brosnan, Miley Cyrus, Neil Young, Robin Thicke, Shannen Doherty and Gerard Butler.