By Neil Smith
Entertainment reporter, BBC News
Director McG has said the hi-tech film will "push the envelope"
The new Terminator movie will "reinvigorate the franchise", Hollywood director McG has promised at a preview of footage in central London.
The film-maker also said the film, Terminator Salvation, would "push the envelope" with its hi-tech visual effects.
Set in 2018 in the aftermath of a nuclear holocaust, the film depicts a "dirty, gritty, difficult" world in which human survivors are preyed upon by lethal robots.
Batman actor Christian Bale plays John Connor, leader of the resistance against the cyborg army.
"When he came on board I knew we had the chance to do something special," the director told reporters.
Other cast members include Bryce Dallas Howard, Australian Sam Worthington and Anton Yelchin, soon to be seen in the new Star Trek film.
However, McG refused to confirm or deny reports that original star Arnold Schwarzenegger, now governor of California, would make a cameo appearance.
"The T-800 is a big character in the film," he said cryptically, referring to the serial number given to the first Terminator model.
But because he was forbidden from revealing more, he said we would have to "let your imaginations run riot".
It has been rumoured that Schwarzenegger has allowed his likeness to be digitally mapped onto a Terminator's face.
Christian Bale has signed up to three Terminator films
The five-minute extended trailer presented an action-packed montage of explosions, stunts, gunplay and car chases.
It also revealed the range of robots featured in the film, among them two-wheeled machines dubbed Mototerminators, tentacled Hydrobots and giant, armoured Harvesters.
Despite this, McG - real name Joseph McGinty Nichol - played down comparisons with last year's Transformers film.
"Transformers is an excellent movie, but our film is not about big robots," he told the BBC News website.
"I wanted it to have lots of hardware and velocity, but I didn't want to hang the whole movie on it."
The US director also revealed he had a plot in mind for a further two instalments in an envisioned second Terminator trilogy.
"We have arced out stories for two more films to a large degree," he said.
Released in 1984, James Cameron's The Terminator went on to spawn two sequels and a TV series, The Sarah Connor Chronicles.
McG said he had made a courtesy visit to the Oscar-winning director before agreeing to take on Terminator Salvation.
"I wanted him to be aware and be on top of what we were up to," the 40-year-old revealed.
Schwarzenegger played the Terminator in three blockbuster films
The Titanic director, he said, "didn't give us his blessing" but was not entirely dismissive either.
Stan Winston, the special effects pioneer who designed the iconic Terminator endoskeleton, was involved in the new film prior to his death in June.
McG, whose previous films include Charlie's Angels and its 2003 sequel, said he intended to dedicate the movie to the late designer's memory.
Terminator Salvation will be released in the US on 22 May 2009 and in the UK on 5 June.
The director joked he hoped his film would perform considerably better than Star Trek, which is to be released on both sides of the Atlantic on 8 May.