World leaders on Friday were pressing for action against Moamer Gaddafi as the Libyan strongman's brutal crackdown on a nationwide revolt escalated, with reports of thousands killed and wounded.

France and Britain have proposed the UN Security Council pass a resolution calling for sanctions and a total arms embargo against Libya ahead of its meeting later to discuss the crisis, France's top diplomat said.

Foreign Minister Michele Alliot-Marie also said they would propose bringing members of the Libyan regime before the International Criminal Court for crimes against humanity.

"There can be no impunity," she said, adding that sanctions could include travel bans for members of Gaddafi’s regime or financial measures.

"I would like there to be a strong (Security Council) resolution in response to Gaddafi’s calls to murder," she added.

An EU diplomat later said European nations were preparing to participate in enforcing a no-fly zone over Libya to protect anti-Gaddafi protesters from strafing should the United Nations approve such a measure.

UN human rights chief Navi Pillay meanwhile told the body's Human Rights Council meeting in Geneva that the crackdown was "escalating alarmingly" and that some sources said thousands of people had been killed or wounded.

"In brazen and continuing breach of international law, the crackdown in Libya of peaceful demonstrations is escalating alarmingly with reported mass killings, arbitrary arrests, detention and torture of protesters," she said.

Diplomats at the UN headquarters in New York said they are studying a possible no-fly zone over Libya, as well as a travel ban and assets freeze against the Gaddafi family.

"All options are on the table. We are not ruling anything out," a Western diplomat said Thursday, speaking on condition of anonymity.

The 15-nation Security Council is determined to show international anger after Gaddafi rejected calls from US President Barack Obama, other heads of state and the council itself for a halt to the violence, diplomats said.

But they noted that sanctions are unlikely to be agreed upon by Friday's meeting, when UN Secretary General Ban Ki-moon will address envoys.

Ban has already expressed outrage over Gaddafi’s actions and warned of international action against those responsible for the violence.

Obama and French President Nicolas Sarkozy on Thursday renewed their call for an end to the "continuing brutal and bloody repression and to the threatening statements of the Libyan leadership," the French presidency said.

After speaking over the phone, the two presidents "reiterated their demand for an immediate halt to the use of force against the civilian population."

In a separate conversation, Obama and British Prime Minister David Cameron promised to "coordinate on possible multilateral measures on Libya," Cameron's office said.

The joint action between the two leaders would include moves at the UN Human Rights Council meeting in Switzerland. Western nations are seeking to have Libya kicked out of the international body.

The Security Council released a statement on Tuesday condemning the Gaddafi regime's attacks on protesters and calling for action against those responsible.

It was the world body's first comment on the protests and unrest that have swept the Middle East and North Africa, driving the longtime leaders of Tunisia and Egypt from power.

Though diplomats stressed there was unity on the council about the need for new measures on Libya, some have said sanctions are likely to be left first to the European Union and United States.

"There was a clear sense that Security Council members want to continue the momentum in terms of the strong unanimity that the council has to address this violence," said another Western diplomat, speaking on condition of anonymity.

The European Union and United States have already threatened sanctions against Libya.

China and Russia, two of the five permanent Security Council nations with veto powers, traditionally resist sanctions against sovereign countries, but a Chinese diplomat said his country was ready to "consider" further action.

China has taken a tougher line on Libya as it has had to move thousands of nationals out of the strife-torn nation.

Russia has said the the use of force against civilians in Libya is "unacceptable," but Prime Minister Vladimir Putin also warned the West against interfering in other countries' internal affairs.