A newly minted American citizen, rocker Neil Young penned a scathing open letter to President Donald Trump Tuesday.

The opening line: "You are a disgrace to my country."

The Canadian-born Rock and Roll Hall of Famer criticized the president about climate change.

"Your mindless destruction of our shared natural resources, our environment and our relationships with friends around the world is unforgivable," Young wrote. "Your policies, decisions and short term thinking continue to exacerbate the Climate Crisis."

Young revived his years-old beef over Trump's use of his song "Keep on Rockin' in the Free World" at rallies and political events. Since June 2015, Young has said he does not approve of Trump's use of the song, admitting he doesn't have any legal recourse to stop him, writing on his website "Legally, he has the right to, however it goes against my wishes.”

The 74-year-old closed his letter by endorsing Bernie Sanders, saying the candidate "is not pandering to the industries accelerating Earth's Climate Disaster, the end of the world as we know it....His initials are BS. Not his polices."

Young has a long history of criticizing what he sees as injustice. In 1970, he excoriated the killing of Vietnam War protesters at Kent State University on the Crosby, Stills, Nash and Young classic "Ohio."

On "She Showed Me Love," a song on his latest album, "Colorado," released in October, he vengefully slashes back at those who have violated his lover, who, in an allegorical turn, is “Mother Nature.”

Contributing: Bob Doerschuk