America's powerful pro-gun lobby group the National Rifle Association has again taken aim at Australia's gun laws, this time targeting the buyback scheme launched in the wake of the Port Arthur massacre.

The NRA posted a video on its official YouTube page on Thursday featuring President Barack Obama and Democratic presidential candidate Hillary Clinton discussing Australia's gun laws.

"Certainly, the Australian example is worth looking at," Mrs Clinton says in the clip.

The clip then uses a series of government advertisements from Australia's 1996 gun buyback, to show "what they're talking about when they're talking about Australia".