The Men in Black 3 trailer has just hit YouTube and it has been confirmed that Will Smith and Tommy Lee Jones are back.

Summer 2012 will bring Agent J (Smith) and Agent K (Jones) in what appears to be a time-travelling, alien-shooting, 3D adventure.

In the trailer, Smith can be seen playing his old character for the first time in ten years after signing up in 2010 and rejecting offers from another film 'The City That Sailed.'

In May 2010, director Barry Sonnenfeld confirmed that both Smith and Jones would be returning to the Men in Black franchise.

The Trailer shows Agent J travelling back in time to see his partner K in 1969 when he was just starting out in the secret government agency.

Delays to the production of the film have plagued director Barry Sonnenfield with a series of script issues and holiday breaks.

The first two Men in Black films made over $1billion at the box office and Sony believes that the third outing will be even better.