TOKYO: It could be the biggest heavyweight fight in history.

Weighing in at four tons, a Japanese company's four-metre (13 foot) high Kuratas robot is set to clash with a US rival's MegaBot in a clash straight out of a Transformers movie.

Suidobashi Heavy Industry took up the giant challenge in a weekend video, as the Japanese firm's chief Kogoro Kurata admitted that his country's robot culture was at stake.

"Yeah. I will fight. Absolutely," he declared on the YouTube video with English subtitles.

"But you know, we really need a melee combat. If we are going to win this, I want to punch them to scrap and knock them down to do it."

Kurata -- draped in a Japanese flag emblazoned with the words "hydraulic pressure" -- was responding to MegaBots' challenge to let its paintball-firing titan square off against Suidobashi's best.

"Suidobashi, you have a giant robot. We have a giant robot. You know what needs to happen. We challenge you to a duel," said the firm's executives, wearing sunglasses and draped in American flags.

"Both of our robots need modification to become combat ready. Prepare yourselves and name the battlefield. In one year, we fight."

It was not immediately clear where the duel would be held or the rules of engagement.

But Kurata wasted no time in slamming his American rivals' robot, which they promised was outfitted with "Really. Big. Guns".

"Come on guys, make it cooler. Just building something huge and sticking guns on it. It's super American," Kurata said to the delight of his fans in cyberspace.

"I cannot let another country win this. Giant robots are Japanese culture