Speaking to Total Film (via CBM), del Toro had the following to say about these massive scaled fist fights:
"We had a Tokyo scene that we shot here in Toronto. We had several Hong Kong scenes and a few scenes in Australia, through the television. We briefly see the kaiju take over San Francisco. The whole Pacific Rim needs a sense of danger."
"We take the battles far and above! Two or three of them happen in places where there have never been a battle between kaiju and robots. From the bottom of the ocean to the atmosphere of the Earth. We have a battle in a storm at sea. Every battle we try to do differently. One is seen from the point of view of a single person. We never cut away from that point of view."
The film stars a versatile cast of manly men, cute Japanese girls and Charlie Day, including; Charlie Hunnam (Sons of Anarchy), the aforementioned Day (Horrible Bosses), Rinko Kikuchi (The Brothers Bloom), Max Martini (The Unit), Willem Dafoe (Speed 2: Cruise Control?), Robert Kazinsky (er, Eastenders), Clifton Collins Jr. (Star Trek), Diego Klattenhoff (Homeland) and Ron Perlman (Sons of Anarchy).
Pacific Rim is due for release the Summer of 2013 and can release a trailer any time now, thank you very much.