Only "a modicum" of force has been used against opposition demonstrators and the government was "taken aback" by the sanctions, Libyan Foreign Minister Mussa Kussa said in a letter sent to the UN Security Council on Friday.
The regime called for the travel ban and assets freeze ordered against Gaddafi and his entourage "to be suspended until such time as the truth is established."
Kussa demanded that the Security Council "stand up to the states that are threatening force against it."
The letter was the first official reaction communicated to the United Nations since the sanctions were unanimously passed by the council last Saturday.
Rights groups say some 6,000 people have been killed since protests against Gaddafi erupted on February 15. The United Nations says that more than 1,000 have died.
Libyan rebels said Friday they had seized a key oil refinery town in some of the heaviest fighting of the rebellion that left "many dead", a claim denied by a senior government official.
A Security Council diplomat, speaking on condition of anonymity, said: "It’s just another example of the regime’s refusal to accept the consequences of their actions.
"However, it also shows that they are rattled by the firm and united action taken by the international community."
China and Russia, traditional opponents of sanctions, have joined in international condemnation of violence used against demonstrators.
However Kussa said security forces had acted only against "subversive acts."
"Where a modicum of force has been used, it has been against law-breakers that have included extremist elements who have exploited others in order to commit acts of destruction and terrorism," the letter said.
The regime's foreign policy chief said opponents aimed to "spread anarchy and attack and burn security locations and police stations, seize weapons and kill soldiers and civilians."
Kussa added: "We believed that the Security Council would understand that the measures that have been taken are consistent with the duty of a state to maintain
security and were consequently taken aback by the adoption" of sanctions.
He said the regime had instructed that "greatest restraint" be used and that "full respect" be shown for human rights.
Authorities have ordered that medical and food supplies must reach all parts of the country, Kussa said. UN emergency aid coordinator Valerie Amos earlier cited unconfirmed reports that relief supplies were being blocked in Tripoli.
The Security Council also ordered an investigation into whether crimes against humanity have been committed in the crackdown. The regime said that Libya is not a member of the International Criminal Court and it would cooperate only on "the principle of the primacy of national courts."
The letter said an independent judicial committee had already been set up to investigate "events."
Kussa said that military action against Libya would be "inconsistent" with the UN charter and international law and "compromise a threat to peace and security in the region and indeed the whole world."
Western powers say they are studying a no-fly zone against Libya to prevent attacks on civilians. But diplomats say that no official request for such action has been made to the Security Council.