US President Donald Trump has demanded that Sweden "give ASAP Rocky his freedom" in a series of tweets.
The musician, real name Rakim Myers, has been charged with assault causing actual bodily harm in Stockholm. He will remain in custody until a trial takes place.
Mr Trump said on Twitter that Sweden had "let our African American community down".
ASAP was arrested on 3 July following a fight that was captured on video.
Two other men who were with them at the time have also been charged with assault. The musician says that his group was being followed by a group of men and he acted in self-defence.
Donald Trump said last week that he had spoken to Swedish prime minister Stefan Lofven about ASAP's case.
However on Thursday the president wrote that he was "very disappointed" in Mr Lofven for being "unable to act" and urged him to "treat Americans fairly".
Give A$AP Rocky his FREEDOM. We do so much for Sweden but it doesn’t seem to work the other way around. Sweden should focus on its real crime problem! #FreeRocky— Donald J. Trump (@realDonaldTrump) July 25, 2019
A spokesperson for Mr Lofven responded by saying that the Swedish judicial system, prosecutors and courts were independent, the government was not allowed to influence legal proceedings and "everyone is equal before the law".
Daniel Suneson, the Swedish prosecutor in charge of the case said that he had not spoken to any White House representatives or any representatives of the Swedish government while investigating the case.
He added that there was "an obvious risk that these three suspects would leave the country if they were released".
On Wednesday, the rapper's mother pleaded for the release of her son. Renee Black told Swedish newspaper Expressen that ASAP "isn't really eating properly."
Other celebrities such as Kim Kardashian West and Kanye West have also called for ASAP's release. More than 500,000, including fellow artists Nicki Minaj and Post Malone, have signed an online petition calling for the rapper to be released on bail.
The trial is due to start on 30 July.
How ASAP Rocky's arrest unfolded
A video published online appears to show ASAP Rocky punching another man in the street.
In videos posted to ASAP Rocky's Instagram afterwards, he and the people he's with repeatedly tell a pair of men to stop following them.
One of the men accuses the 30-year-old's team of breaking his headphones.
In the caption for the first video ASAP Rocky writes: "We don't know these guys and we didn't want trouble. They followed us for four blocks."
In the second, he accuses the man of hitting his security guard "in the face with headphones".
The 30-year-old was in Stockholm to perform at Smash festival.