LOS ANGELES — A California man pleaded guilty Friday to a federal terrorism charge after admitting he attempted to assist al-Qaida by providing weapons training, the U.S. attorney's office said.

Sinh Vinh Ngo Nguyen, 24, of Garden Grove entered the plea before U.S. District Court Judge John F. Walter, who scheduled sentencing for March 21, prosecutors said in a statement. Nguyen faces a maximum of 15 years in federal prison.

The statement said Nguyen's admission was contained in a plea agreement filed in federal court.

"Nguyen admitted that approximately one year ago he traveled to Syria where he joined opposition forces," the statement said. "Using a social network site during a four-month period he was in Syria, Nguyen told people that he was fighting against the Assad regime and that he had had a 'confirmed kill.'"

Nguyen returned to the U.S., where he told associates that he had offered to train al-Qaida forces in Syria but was turned down, the U.S. attorney's office said.

Prosecutors said that between Aug. 3 and Oct. 11 Nguyen met with a man he thought was an al-Qaida recruiter but who actually was working for the FBI, telling him about what he'd done in Syria and saying he wanted to return to jihad.

On Oct. 1, Nguyen purchased a ticket for travel from Mexico to Pakistan and he was arrested by FBI agents on Oct. 11 as he was about to board a bus from Santa Ana, Calif., to Mexico.

TRIONE MAKES HIS MARK

1948: Opens Sonoma Mortgage Co. in downtown Santa Rosa, offering home loans at 4 percent, 2 points below the going rate.

1968: Merges the mortgage company into Wells Fargo Bank, gaining $10.6 million in the bank's stock and a seat on the board of directors.

1972: Acquires 5,000-acre Annadel property in $5 million deal that thwarts development and leads to creation of state park on Santa Rosa's eastern flank.

1981: Organizes group of civic leaders who acquire the Christian Life Center for $4.5 million in a bankruptcy court bidding war. It is now the Wells Fargo Center for the Arts.

1982: Sells interest in Oakland Raiders, after winning three Super Bowl rings, when Al Davis moves team to Los Angeles.

1990: Nearly killed when a 1,200-pound horse topples on him during a trail ride on his ranch near Yorkville.

"A broken neck, huh?

That's probably not gonna help my golf game," he tells a doctor.

1998: Sells Geyser Peak Winery to a conglomerate for $100 million, 16 years after buying the winery for $20 million.

2011: Long retired from business, still involved in philanthropy. Divides his time between hillside home adjoining Annadel State Park and winter home in Palm Desert.