US President Barack Obama came out fighting on Tuesday in his second debate against Mitt Romney, branding the Republican challenger a tool of the rich and the oil industry.

"Governor Romney says he has a five-point plan. He doesn't have a five-point plan. He has a one-point plan, and that is to make sure that folks at the top play by a different set of rules," Obama said.

"That's been his philosophy in the private sector, that's been his philosophy as a governor, and that's been his philosophy as a presidential candidate. You can ship jobs overseas and get tax breaks for it."

Responding swiftly and fiercely to Romney's comments, standing face to face with his opponent, Obama defended his clean energy record and declared: "His plan is to let the oil companies write the energy policy."

The Democratic incumbent is generally regarded as having come off worst in the pair's first head-to-head encounter on October 3, and polls suggest the race is extremely close with only three weeks until polling day.

VietNamNet/AFP