The three-paragraph, unanimous decision from a three-judge panel of the 4th U.S. Circuit Court of Appeals in Richmond rejects both Manning's argument that she was erroneously found in civil contempt of court and her request for bail while the contempt decision is litigated.
Manning has been jailed at the Alexandria Detention Center since March 8 after refusing to testify to the Wikileaks grand jury.
Since her incarceration, criminal charges against Wikileaks founder Julian Assange have been unsealed and U.S. officials have requested his extradition . Manning's lawyers argued that her testimony is unnecessary in part because Assange has already been charged.
Manning's lawyers also argued that she told authorities everything she knew during her court-martial investigation and that her incarceration was unnecessarily cruel because the jail is unable to provide adequate medical care in connection with gender-reassignment surgery Manning underwent.
Prosecutors responded that they believe Manning, who was granted immunity for her grand jury testimony, may have more to say about her interactions with Wikileaks than has been previously disclosed, and that Manning is out of line for disrupting the grand jury process simply on her speculation that she is being singled out for harassment. They also say that the jail has gone out of its way to accommodate her medical needs.
Prosecutors have called Manning's leak to Wikileaks one of the largest compromises of classified information in U.S. history.
Manning said in a statement issued through her legal team that she is considering an appeal to either the full 4th Circuit or to the Supreme Court.
"I don't have anything to contribute to this, or any other grand jury," she said. "While I miss home, they can continue to hold me in jail, with all the harmful consequences that brings. I will not give up."
Her lawyer, Moira Meltzer-Cohen, said she does not believe Manning's testimony is necessary to the grand jury.
"The likely purpose for her subpoena is to help the prosecutor preview and undermine her potential testimony as a defense witness for a pending trial" of Assange, she said.
Under the terms of the judge's contempt finding, Manning will remain jailed until she agrees to testify or until the grand jury's term is concluded. That date is unknown.