Tesla CEO Elon Musk apparently suggested implementing a tax on carbon emissions to President Donald Trump, Bloomberg reported Thursday.

His idea wasn’t well-received, a senior White House official told Bloomberg, as Trump’s officials failed to support his suggestion.

Musk, who is also CEO of SpaceX and is a member of Trump’s Strategic and Policy Forum, met with the president Monday along with other corporates from Under Armour, Whirlpool, Ford, Dow Chemical and Lockheed Martin. During the meeting, Trump promised the executives he would cut corporate taxes and regulations.

Like Musk, retired ExxonMobil CEO Rex Tillerson, Trump’s Secretary of State pick, also previously supported a carbon tax. Musk expressed his support for Tillerson, this week via Twitter.

Trump And Tillerson’s Difference On Climate Change

Tillerson has previously acknowledged the climate is changing, but Trump has called global warming a “hoax” invented by the Chinese.

After the inauguration, Trump’s administration deleted climate change references from the White House website, and his transition team for the Environmental Protection Agency is reportedly planning massive cuts at the agency and ending funding for scientific research.