MUAMMAR Gaddafi says the UN resolution authorising international military intervention in Libya is "invalid".

The Libyan leader says he sent a message to US President Barack Obama defending his decision to attack rebel cities: "If you found them taking over American cities by the force of arms, tell me what you would do."

The statement came from the government spokesman at a news conference in Tripoli.

Mr Gaddafi also sent a letter to the French and British leaders, and the UN secretary general, saying the resolution violates the UN charter and saying they would "regret" any intervention.

"Libya is not for you, Libya is for the Libyans," he said.