A well-known performance artist and activist has declared he will run as a US presidential candidate on a free pony platform.

Vermin Supreme filed his paperwork for the New Hampshire presidential primary ballot on the last day before applications closed, along with the registration fee of $US1,000 — which he paid in $50 bills marked "not to be used for bribing politicians".

The bearded eccentric, who regularly sports a boot on his head, has been running for public office since 1987.

His platform includes a promise of a free pony for every American citizen and a plan for the "inevitable zombie invasion".

"The pony-based economy is truly the most important issue in America today. Fossil fuels are literally killing the planet, and today, we stop that," he told the crowd gathered for his filing.

"We don't need no more cars, we have ponies.

"And when we have ponies, my friends, we are going to have a beautiful time."

He also said he would go back in time to kill Adolf Hitler, a plan which Republican nominee Jeb Bush weighed in on in a recent interview with the Huffington Post.

Dragging a bag full of plush ponies through the New Hampshire state house, Mr Supreme was asked by reporters how he would defeat the Islamic State militant group.

"Lots of ponies — pony bombs, pony drones, pony tanks, pony troops, hoofs on the ground, boots on the head," he said.

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Before he could re-enter the building to officially file his paperwork, he was stopped by security and asked to remove a number of weapons — including a gun strapped to the outside of his gumboot and a giant toothbrush he carries to promote mandatory dental hygiene.

"Here in New Hampshire open-carry [of weapons] is the law ... but secret service made me take my guns off, sorry about that," he told reporters.

This year Mr Supreme is running for the Democrats, but in the past he has campaigned for the Republican party noting he "leaned towards anarchism".

Mr Supreme's final message to the press conference?

"Together my friends, we will ride our ponies into a zombie-powered future."