After its first season, Steve Jones was axed as the presenter of the Fox series.
"I want to work with a boy and girl and I definitely think this is a role for two people," Cowell told reporters in Canada. "I can't say who it is - but they have narrowed it down to five people.
"As far as I'm concerned, and I don't think it's going to change, it will be a boy and girl and neither of them will have hosted before."
Cowell is currently preparing for the show's second season later this year, which will also welcome new judges Britney Spears and Demi Lovato.
Spears and Lovato replaced former judges Paula Abdul and Nicole Scherzinger, the latter of whom recently joined X Factor UK.
Cowell also explained why he called Spears and Lovato the "gruesome twosome."
"Britney is fearless. To get a no out of Paula, as you know, was like getting blood out of a stone because she didn't' want to be unpopular," said Cowell.
"Britney - there's no qualms. She could have 4,000 people going crazy about a contestant, 'No' - can you back it up? - 'No.'
"Then when the two of them get together and me and LA want someone to go through, these two, they gang up - and that's what happens when you put two girls together!"
Watch a clip of first season winner Melanie Amaro on X Factor USA below: