A court in Vietnam on Monday sentenced a U.S. citizen to 12 years in prison after finding him guilty of "attempting to overthrow the state" in a trial that lasted just half a day, his lawyer said.

Michael Phuong Minh Nguyen, 55, pleaded guilty, but had asked that his sentence be reduced so he could be reunited with his family, his lawyer Nguyen Van Mieng told Reuters by telephone after the trial at the Ho Chi Minh City court.

Nguyen will be deported after serving his jail sentence.