McCabe was fired from his role as the No. 2 official in the FBI on Friday by U.S. Attorney General Jeff Sessions.
Trump said the firing was also “a great day for the hard working men and women of the FBI.”
Trump then took a shot at James Comey, McCabe’s former boss whom Trump fired in May 2017, declaring him to be “sanctimonious” and that he made “McCabe look like a choirboy.”
The move to fire McCabe looks to be spiteful given that it came two days before McCabe’s 50th birthday, when he could have retired with full pension.
McCabe had stepped down from his position as FBI deputy director in January but remained on leave pending retirement.
WATCH: Former FBI deputy director Andrew McCabe fired by Jeff Sessions days before retirement
In a statement, McCabe said he believes he was politically targeted because he corroborated Comey’s claims that Trump tried to pressure him into killing the Russia probe.
Trump acknowledged he fired Comey over “this Russia thing” in a TV interview.
“I am being singled out and treated this way because of the role I played, the actions I took and the events I witnessed in the aftermath of the firing of James Comey,” McCabe said in his statement.
“This attack on my credibility is one part of a larger effort … to taint the FBI, law enforcement and intelligence professionals more generally.”
On Friday, Sessions said he fired McCabe after it was discovered he leaked information to reporters and misled investigators about his actions.
“The FBI expects every employee to adhere to the highest standards of honesty, integrity and accountability,” Sessions said.
*With files from Reuters