President Donald Trumps video address to the World Economic Forum in Davos.

 US coal producers’ shares climbed after President Donald Trump promoted the fuel as a power source during a video address Thursday to the World Economic Forum in Davos, Switzerland.

Peabody Energy, the top US coal miner, surged as much as 7.6%, the most intraday since the day following the November presidential election. Core Natural Resources gained as much as 2.9% and the Russell 3000’s coal subsector index rose as much as 4.2%.

Trump’s support for fossil fuels is well known, but coal didn’t receive as much attention during this campaign as it did in prior elections. The new president is seeking to revamp US energy policy with an increased focus on oil and natural gas, and his comments Thursday demonstrated he also is keen to bolster the dirtiest fossil fuel.

“Nothing can destroy coal. Not the weather, not a bomb,” Trump told attendees at the economic conference. “It’s a great backup.”