A$AP Rocky's trial for assault next week

The man allegedly assaulted by American rapper A$AP Rocky and two other men in Stockholm was kicked while on the ground and hit with a bottle, Swedish prosecutors say in court documents.

The 500 pages of documents also included allegations that Rocky pushed the man to the ground and photos of the alleged victim's cuts, bruises and blood-stained clothes.

The Grammy-nominated rapper and the two others "deliberately, together and in agreement" attacked the man, identified as Mustafa Jafari, on June 30, prosecutors said in the Stockholm District Court documents filed on Friday.

Rocky, whose real name is Rakim Mayers, has said he acted in self-defence. He has been in custody since July 3 and faces charges that carry a maximum sentence of two years in prison.

A lawyer for Jafari, Magnus Stromberg, said the alleged beating started when one of A$AP Rocky's guards "grabbed him by the neck and dragged him away".

Jafari didn't provoke the assault, and "this situation has been very stressful for him", Stromberg said.

"There was no reason, none whatsoever, for the use of such violence," he said.

Rocky's arrest prompted US President Donald Trump to intervene on behalf of the jailed rapper and sparked an unusual diplomatic spat when Swedish prosecutors charged the 30-year-old artist on Thursday.

Trump posted two sharply worded tweets, calling on Sweden to "Treat Americans fairly!" and criticising Swedish Prime Minister Stefan Lofven, whom he had spoken with directly, "for being unable to act".

A Lofven spokesman responded by emphasising the independence of the Swedish judicial system.

The case also drew the attention of American celebrities like Kim Kardashian West and Rocky's fellow recording artists, including Sean "Diddy" Combs and Justin Bieber.

The rapper and the other two suspects, who have been described as members of his entourage, will remain in custody until trial.

Prosecutors recommended that the Stockholm District Court set aside three days for the trial, which defence lawyer Slobodan Jovicic said was expected to start on Tuesday.

Trump last Saturday tweeted that he had spoken with Lofven about the case and "offered to personally vouch for his bail" even though that's not something available under Swedish law.

Urged on by the first lady and celebrities including Kardashian West, the president had said that he would intervene to try to free Rocky.

Lofven's press secretary, Toni Eriksson, later said the two leaders had a "friendly and respectful" conversation in which Lofven "made certain to emphasise the complete independence of the Swedish judicial system, prosecutors and courts" and stressed that the government cannot and will not attempt to influence the legal proceedings.