"We have to recognise it: negotiations have failed. Time is not on our side. I am not sure this view is shared in London, Berlin or Paris. But that is a mistake," Bolton told Le Monde newspaper.
"The only response is to isolate (the Iranians) internationally as well as politically and economically. In the long term, in the I hope not very long term, the only real solution is regime change," he said.
Asked if this was the policy of the US administration, he said: "No. Regime change is not part of their working framework."
On the issue of Iraq, Bolton — a key supporter of the 2003 invasion — said that he "continued to think that the basic decision to overthrow Saddam Hussein was the right one."
"Retrospectively we should have transferred authority to the Iraqis more quickly," he said.
Asked about President George W. Bush’s plans to send in troop reinforcements to stem the violence in Iraq, he said it was the US’s "last effort."
"If the Iraqis cannot straighten the situation, that’s their fault," Bolton said.