Democratic presidential candidate Joe Biden called Donald Trump "a climate arsonist"
US President Donald Trump has dismissed concerns over climate change on a visit to fire-ravaged California, telling an official "I don't think science knows" about global warming.
"It'll start getting cooler, you just watch," Trump said after he was urged not to "ignore the science", reports the BBC.
Blazes in California, Oregon and Washington state have burned almost 2m hectares (5m acres) of land and killed at least 36 people since early August.
Trump blames poor forest management.
During his visit to the US West Coast, Trump - who has often denied climate change - repeated his argument on forest management as he met Californian officials involved in the battle against the wildfires.
Earlier on Monday, Democratic presidential candidate Joe Biden called Donald Trump "a climate arsonist".
In 2018, the president criticised California's forest management, pointing to Finland, where he said they raked and cleared the forests to prevent fires.
When asked by a reporter whether climate change was a factor in the massive wildfires, Trump responded: "I think this is more of a management situation."
He also claimed that other countries had not dealt with the same level of forest fires, despite major conflagrations in Australia and the Amazon rainforest in recent years that experts attributed to the changing climate.
"They don't have problems like this. They have very explosive trees, but they don't have problems like this," the US president said.
He added: "When you get into climate change, well is India going to change its ways? And is China going to change its ways? And Russia? Is Russia going to change its ways?"
Donald Trump has previously called climate change "mythical", "non-existent", or "an expensive hoax" - but has also described it as a "serious subject".
He pulled the US out of the Paris climate agreement, which committed the US and 187 other countries to keeping a global temperature rise this century well below 2C (3.6F) above pre-industrial levels.