Rebecca Hall's scientist Maya Hansen appears for the first time in the pictures, which also include shots of the Iron Patriot armour and the battered Iron Man mask.
Robert Downey Jr reunites with his Kiss Kiss Bang Bang writer-director Shane Black on the third film, which will see Tony Stark on a revenge mission against those who "destroyed his private world".
He ultimately faces off against the Mandarin (Ben Kingsley), who is described as Iron Man's most powerful enemy yet.
Despite the dark tone of the first trailer – which showed Stark's home being destroyed and a mysterious figure attacking Pepper Potts (Gwyneth Paltrow) in bed – producer Kevin Feige recently insisted that Iron Man 3 "is not a serious movie".
> 'Iron Man 3' trailer: Scene-by-scene recap - pictures
> 'Iron Man 3' gets early UK release
Iron Man 3 will be released on April 26 in the UK, and May 3 in the US.
Watch the teaser trailer below:
Gallery - Iron Man 3: