RICHMOND, Va. (AP) — Justice Department prosecutors have urged a federal appeals court to uphold a prison sentence of more than 13 years for a former Coast Guard officer accused of plotting a terrorist attack inspired by infamous mass murderers and far-right extremists.

The arguments from federal prosecutors in Maryland came in a court filing Friday, about three months after attorneys for Christopher Hasson asked the 4th U.S. Circuit Court of Appeals to let him withdraw his guilty plea or else throw out his sentence. The main area of contention in the appeal case is whether a federal judge in...