The property tycoon beat Democrat Hillary Clinton in a stunning election upset in November (16) and the outspoken punk star now believes he's out to get those who didn't support him.
"Trump is not only taking out his revenge on the people who protested him, but also the average American that just didn't vote for him," the singer writes in a statement posted on Instagram.
His written thoughts come after the President spent his first week in office reeling off a series of executive orders, including a contentious travel ban on Muslims from seven countries.
"I feel like I'm in a state of shock," Billie Joe writes. "The executive orders Trump is signing feels like a vendetta.
"These reckless decisions on healthcare, Muslim-Americans, immigration, environmental protection, freedom of speech, freedom of press, women's right to choose what to do with their bodies, suggesting sending in the feds to Chicago... are signs of a man that is trying to redefine what it is that keeps our common union as Americans."
He added: "This is not just his 'conservative agenda'. It's an all out assault on our civil liberties. His intention is to divide us as Americans..."
The 21 Guns rocker has urged fans to respect each other and show compassion to one another regardless of their political leanings, adding, "I don't think this president has a grasp on the concept of the American dream... the dream that we come from different backgrounds to come together," Armstrong wrote. "Please don't allow this madman to take out his revenge... on US."