After a week, Mohamed said he was taken to a deportation facility where he was visited by three FBI agents. He said they asked him why he went to Yemen and Somalia, saying his travels "raised red flags." He said he refused to talk to them without a lawyer present.
A State Department spokesman said the U.S. government had no role in Mohamed's initial detention. The Kuwaiti Embassy in Washington did not respond to a request for comment.
During a second visit to the detention center, Mohamed said, the FBI agents suggested that he had joined terrorist camps in Somalia and Yemen but that, perhaps, he was now a "changed man." They asked him to become an informant for the bureau, an offer he declined, he said.
He said his plans are to attend George Mason University and study information technology.
His family said they have been shaken by the experience. "We did not expect this from America," said his brother, Leeban Mohamed, 24. "We've seen America change."
The no-fly list is maintained by the Terrorist Screening Center, which is overseen by the FBI. In a redacted submission to the court in Portland, Christopher M. Piehota, deputy director for operations, said the TSC receives information about suspected domestic and international terrorists from the FBI and the National Counterterrorism Center.
To make the general database, there must be a "reasonable suspicion to believe that a person is a known or suspected terrorist," the government said in court papers. To be placed on the no-fly list "additional derogatory information must exist demonstrating that the individual meets the requisite criteria."
On Friday, a federal judge continued a hearing on a government motion asking her to dismiss the ACLU complaint, saying she wanted further briefings.
Staff writer Tara Bahrampour and staff researcher Julie Tate contributed to this report.