Former prime minister Kevin Rudd has branded a new US gun lobby advert which targets President Barack Obama and his children "one of the most offensive of all time".

The National Rifle Association (NRA) posted the advert on its website and YouTube.

It questions why President Obama's children have secret service guards while Obama himself remains sceptical about allowing armed guards into US schools.

"Are the president's kids more important than yours?" the advert says, before branding President Obama an "elitist hypocrite".

But Mr Rudd, now a Labor backbencher, slammed the 34-second video and said no political leader anywhere in the world should have to put up with it.

"The US National Rifle Association TV ad on President Obama's kids is one of the most offensive ads of all time," he posted on Twitter on Thursday.

"For the record, I fully support the Australian system of registered gun owners & gun clubs.

"But US NRA is out of control. KRudd."

In a December interview, Obama said he was "sceptical" about an NRA proposal of placing armed security guards at schools around the country.

"I am sceptical that the only answer is putting more guns in schools," Obama told NBC television's Meet the Press.

"And I think the vast majority of the American people are sceptical that that somehow is going to solve our problem."