The 17-year-old star, who is rumoured to be dating former English soccer star David Beckham's son, Brooklyn, said American boys are more bold and open, reported Contactmusic.
"UK boys are way more dangerous because they seem really nice and then it's like a sneak attack. They're cobras.
"You meet them and they're really quiet but secretly they're really crazy. American guys are 'I'm really crazy' or 'I'm really aggressive; and you see it, but with Brits you've got to figure it out," Moretz said.