Former Minneapolis police officer Derek Chauvin - who was convicted last year in the murder of George Floyd - was sentenced Thursday to 21 years in prison on separate federal charges related to violating Floyd's civil rights during his arrest, which led to his death in May 2020.

Chauvin, who pleaded guilty last December to these federal charges, is serving a 22-and-a-half-year sentence in a Minnesota prison after being convicted of Floyd's murder in a state trial last year.

The federal sentence will be executed concurrently, as Chauvin will be transferred to a federal prison.

The ruling was announced by Judge Paul Magnuson in US District Court in St. Paul, Minnesota, saying that he had counted the seven months Chauvin had already spent in state prison, deducting this from his 21-year federal sentence.

After serving the sentence in a federal prison, he will be released on probation for five years.

According to notes written by a journalist inside the courtroom and reported to the media, the judge described Chauvin's actions as "offensive and unscrupulous."

"It is wrong to kneel on someone else's neck until they die, and therefore you should be punished severely," Magnuson said.

Chauvin, 46, admitted that he violated Floyd's right not to be subjected to an "unjustified arrest" when he knelt on his neck handcuffed for more than 9 minutes, in a murder that was filmed on a mobile phone.

Floyd's death led to protests in many American cities and around the world over police brutality and racism.

The judge also ordered that Chauvin pay compensation, the amount of which has not yet been determined.

Chauvin's decision to plead guilty avoided a second criminal trial.