Robert Rodriguez is 'blown away' by Lady Gaga's performance in his upcoming movie Machete Kills.

The director confirmed Thursday that the pop star has been cast as the sultry Lady Chameleon character in the sequel to his 2010 action thriller Machete.

This marks Lady Gaga's debut as an actress and Robert is astonished by how well she depicted her character.

"I just finished working with @LadyGaga on @MacheteKills," Robert wrote on Twitter attaching a movie poster featuring the star. "She kicked SO MUCH A*S! Holy Smokes. Blown away!"

Lady Gaga expressed her enthusiasm about the project shortly after Robert.

'Yes its true, I will be making my debut as an actress in the amazing MACHETE KILLS BY @RODRIGUEZ (sic),' she tweeted. 'IM SO EXCITED!!! AH! Filming was insane.'

The movie follows main character Machete as he is hired by the US government to take down a Mexican arms dealer who aims to launch a weapon into space.

Machete Kills, which hits theatres next year, also stars Danny Trejo as Machete, Charlie Sheen as the President of the United States, Mel Gibson as villainous arms dealer Luther Voz and Sofia Vergara will portray a dominatrix.