In an effort to secure ASAP Rocky's freedom, a U.S. official decided to put a little pressure on the Swedish government.

On Friday night, CNN shared a leaked diplomatic letter in which Robert C. O'Brien, the US Special Presidential Envoy for Hostage Affairs, urged the Swedish Prosecution Authority to resolve the case as quickly as possible. O'Brien wrote the letter on July 31, two days before the Harlem rapper was was granted permission to leave Sweden. The official requested the immediate humanitarian release of Rocky and his co-defendants—David Rispers and Bladimir Corniel—and proposed they be sent to "a supervised detention in a local Stockholm hotel pending final disposition of the case."

After outlining his requests, O'Brien warned that if the case wasn't quickly resolved there would be potential "negative consequences to the U.S.-Swedish bilateral relationship."

Sweden's Prosecutor-General, Petra Lindh, denied the requests, according to a letter dated Aug. 1.

"No other prosecutor, not even I, may interfere with a specific case or try to affect the prosecutor responsible," Lindh wrote to O'Brien. "Furthermore, when a person is charged and the case is brought before a court, only the court can decide, during or after the trial, whether or not to release the person or decide on supervised detention."

We appreciate the decision of Swedish prison authorities to expedite paperwork & allow the parents of A$AP Rocky, David Rispers & Bladimir Corniel to visit their sons in the detention facility. The guards were professional & treated the family & US diplomats with respect. — U.S. Special Presidential Envoy O’Brien (@StateSPEHA) August 1, 2019

You can read both leaked letters at CNN's website.

Swedish authorities arrested Rocky for alleged assault one month ago, after the rapper was filmed fighting a man in the Stockholm streets. Prosecutors have requested a six-month jail sentence for the 30-year-old artist. The final verdict is scheduled for Aug. 14.