A US appeals court has upheld the conviction and sentence of 9/11 conspirator Zacarias Moussaoui. The only person charged in the US over the attacks, Moussaoui had originally pleaded guilty to conspiracy. In 2006, he was sentenced to life in prison for his role in planning the attacks that killed nearly 3,000. During his original trial in 2005, he had testified that his role was to hijack a fifth plane and crash it into the White House.