'Game of Thrones': A 'great war' is warned in teaser trailer - watch
The 15-second clip features a female narrator warning of an impending war that must be won.
"A great war is between death and life, ice and fire," the narrator says.
"If we lose, the night will never end."
The trailer follows a poster which featured the return airdate of March 31, 2013 set in stone.
The third season of the fantasy drama epic based on George RR Martin's Song of Ice and Fire books sees a string of new stars joining the series.
Dame Diana Rigg, Mackenzie Crook, Clive Russell and Kerry Ingram will be among those taking on roles in the upcoming run.
Jon Snow actor Kit Harington recently stated that season three is his "favourite season so far".