The people of Finland have trolled US President Donald Trump on social media after he suggested California should follow the Scandinavian country's lead and do more "raking" to prevent wildfires.

Mr Trump was visiting a town in California - which had been devastated by the recent wildfires - and told reporters on Saturday that wildfires were managed better in Finland because people "spend a lot of time on raking and cleaning and doing things."

In response, Finland President Sauli Niinisto told the Ilta-Sanomat newspaper that he did speak to Mr Trump about forest management, but didn't recall talking about "raking".

Finns woke up to find their country was trending on social media and the comment has inspired them to demonstrate their forest "raking and cleaning" abilities on Twitter.

Mr Trump expressed sadness during his visit on Saturday at the devastation in a California town, as more than 1,200 people listed as missing in the worst-ever wildfire to hit the US state.

Two huge blazes have created a serious smoke problem across vast areas in the state, and when Trump stepped out of Air Force One at Beale Air Force Base north of capital city Sacramento, the sun was struggling to cut through haze so dense it covered the base like a fog.

"This is very sad," Trump said after surveying the remains of Paradise.

The only people out on the road were emergency services workers, surrounded by the twisted remains of the incinerated town.