Ashton Kutcher has described Natalie Portman as the 'best actress of my generation.'
The pair team up for new romantic comedy No Strings Attached - which is directed by Ivan Reitman, and Kutcher admitted that it was a challenge to work alongside her.
Speaking to Cover Media the actor said: "She's probably one of the best actresses of my generation. I believe she is and there's a blessing and a curse in that as an actor.
"Because... you know everything you get across from you is going to be real and honest and reactive and beautiful, at the same time when the light shines in the dark room all the dust shows, and so it was a challenge for me to... be as honest as she is."
And while Kutcher revealed that it was a challenge working alongside the Oscar nominee he enjoyed their chemistry.
"It's easier when you like the person and she's very likeable. I don't know that it's something you can... manufacture.
"I've generally found that you can have really good chemistry with someone that you can argue well with and I think Natalie and I both really appreciate being right and I think that that makes for good chemistry.
"I think Natalie could have chemistry with this cup if she wanted to."
No Strings Attached is the first movie for the actor since he starred in Killers last year. He is currently filing New Year's Eve - which is directed by Valentine's Day filmmaker Garry Marshall.
No Strings Attached is released 25th February.
Tagged in Ashton Kutcher Natalie Portman