An American citizen picked up on the Syrian battlefield and held by the U.S. military for nearly four months without a lawyer has told the American Civil Liberties Union that he wants to challenge his detention, a lawyer for the civil rights group said Friday.

ACLU attorney Jonathan Hafetz said he and two other ACLU lawyers went to the Pentagon on Wednesday and spoke via videoconference with the detainee, who is being held as an enemy combatant accused of fighting with the Islamic State.

"He spoke loud and clear that he wants a lawyer and wants to challenge his detention now," Hafetz said, adding that the detainee also indicated that he wants the ACLU to represent him.

Hafetz said the detainee was born in the United States but would not identify him. He "expressed concerns about his name being released and asked that it not be made public," Hafetz said.

The ACLU filed a court petition months ago, challenging the man's detention and asking to act on his behalf to provide him access to legal counsel. Hafetz said that the detainee told the ACLU that he did not learn that the petition had been filed on his behalf until shortly before the video conference.

Last month, U.S. District Judge Tanya Chutkan ruled that the U.S. military must provide legal counsel to the detainee. The U.S. government had acknowledged that it has detained him without fulfilling his request to see a lawyer. The judge ordered the military to let the ACLU have "immediate and unmonitored access to the detainee" to determine his wishes.

The judge also ordered the Defense Department not to transfer him to another country until the ACLU tells the court of the detainee's wishes. On Friday, the ACLU asked the court to continue to direct the Pentagon not to transfer him.

Kathryn Wyer, an attorney in the Justice Department's civil division, earlier told the court that the U.S. military was working "diligently" on the case, but had not yet decided what to do with the detainee. Wyer cited case law stating the executive branch should be given a reasonable period of time to determine a detained individual's status.

But the ACLU protested his months of detention without access to a lawyer.

"The Trump administration illegally denied an American his rights to access a lawyer and a court for nearly four months, but those efforts have finally failed," Hafetz said. "Now that our client has secured the judicial review that the government attempted to block."