After Trump announced that he'd speak with the Swedish Prime Minister about the country's treatment of the Grammy-nominated rapper, Bieber, 25, retweeted the POTUS.
The President has not yet responded publicly to the "I Don't Care" singer's plea.
Trump initially tweeted about A$AP Rocky's case on Friday, when he said he had spoken to Kanye West about A$AP's — born Rakim Mayers — incarceration. He said he would be calling Swedish Prime Minister Stefan Löfven about the case.
"So many people would like to see this quickly resolved!" he added.
Multiple celebrities, including Kim Kardashian, Sean "Diddy" Combs and Nicki Minaj, have pushed for Rocky's release. First lady Melania Trump said the administration is working with the State Department.
Kardashian thanked Trump, Secretary of State Mike Pompeo and senior Trump adviser Jared Kushner on Twitter Thursday for their "efforts to Free A$AP Rocky & his two friends."
Trump also offered to "vouch for [A$AP Rocky's] bail." While not an option in Sweden, bail is common in the United States. A defendant is allowed to post an amount of money set by the court to guarantee the defendant will appear for trial if he or she is freed pending those proceedings.
Löfven said Saturday that he was aware Trump “has a personal interest in the case” but added that he “cannot and will not attempt to influence prosecutors or courts.”
Fox News' Adam Shaw and The Associated Press contributed to this report.