JJ Abrams admits he thought the new Star Wars was going to be “a f**king disaster!”

Directing one of the most anticipated films in history was always going to come with a multitude of worries.

JJ Abrams has opened up about his concerns for 'Star Wars: The Force Awakens', saying he thought the whole thing was going to be a 'f**king disaster'.

The 49-year-old filmmaker has confessed one of his biggest fears was that the new cast wouldn't work with the actors from the original trilogy, who include Harrison Ford, Carrie Fisher and Mark Hamill.

He said: "We knew we weren’t just casting one movie—we were casting at least three. That, to me, was the biggest challenge.

"When we met Daisy Ridley, when we found John Boyega, and then Oscar Isaac and Adam Driver came aboard, we got really excited. And yes, Daisy and John could work together, but what happens when Harrison's in the mix? What will that feel like? If it doesn't spark, it's a f**king disaster."

The 'Star Trek Into Darkness' director wasn't just worried about the human characters getting on, however, as he admitted he wasn't sure new robot BB-8 would gel with the much-loved droids C-3PO and R2-D2 from the previous films.

He told Wired magazine: "Yes, BB-8 is a great character, amazingly puppeteered, but what will happen when he's suddenly in a scene with C-3PO or R2-D2? Will it feel bizarre? Will it feel wrong? Somehow it didn't. When Anthony Daniels [C-3PO] told me, 'Oh my God, I love BB-8!' I said, 'We're going to be OK'. Because if he's OK, it's working."

And Abrams was thrilled when he realised everything he'd worked so hard to put together was going to come across on-screen.

He added: "It was really exciting to say, 'These scenes are working!' We worked really hard to cast and to write and to put it all together, but you just don't know until you start shooting. Then all of a sudden, you're on-set watching it and you know.

"It's a little bit like having a party and having friends from your new school meet friends from your old school, and you think, 'What's going to happen?' And all of a sudden they're getting along famously and this party's really fun! It was a lot of work, but it ended up being great."

In other words, the Force is strong, real strong...