Lisa Kudrow says a 'Friends' reunion with cast in their forties and fifties would be ''sad''.

The 54-year-old comedienne played hapless busker Phoebe Buffay on the US sitcom for 10 years, and opened up about the possibility of a new series after a fake trailer for a movie adaptation went viral.

Appearing on 'Late Night with Conan O'Brien' with her former co-star Courteney Cox [Monica Geller], she said: ''Courtney [Cox] is actually the one who said, 'You see that trailer, oh my god, what do we do?'

''I was like, 'Nothing, that's just a clip, it's just sort of clips from, like, Cougar Town'.

''She [Courteney] wasn't fooled, she was just like 'Wow, how did that go viral'.

''I know, I don't know what to make of it, it's like sort of these weird clips from things that clearly have nothing to do with Friends and it's called a Friends Movie.''

The NBC series hasn't been on screens for 14 years, with the last episode airing in May 2004.

Jennifer Aniston [Rachel Green] previously said 'Friends' could never happen now because of society's reliance on technology.

The 48-year-old insists scenes of the characters interacting in the Central Perk coffee shop wouldn't reflect modern life as people are too interested in their mobile devices to have proper conversations.

She said: ''We were jokingly saying that if 'Friends' was created today you would have a coffee shop full of people that were just staring into iPhones.

''There would be no actual episodes or conversations.''

'Friends' also starred Matthew Perry [Chandler Bing], Matt LeBlanc [Joey Tribbiani] and David Schwimmer [Ross Geller].