WASHINGTON: US Senator John Kerry on Tuesday denounced Libyan leader Moamer Kadhafi's deadly crackdown on anti-government protests as "beyond despicable" and called for global pressure to end his regime.

The Kadhafi government's "use of deadly force against its own people should mean the end of the regime itself. It's beyond despicable, and I hope we are witnessing its last hours in power," the senior lawmaker said in a statement.

Kerry, who chairs the US Senate Foreign Relations Committee, said Kadhafi was now "irredeemable" and stressed that top Libyan military commanders risked international war crimes charges for any "acquiescence in atrocities."

The lawmaker said all international oil companies "should immediately cease operations in Libya until violence against civilians ceases" and urged President Barack Obama to re-impose US sanctions lifted under his predecessor, George W. Bush, when Tripoli agreed to dismantle its nuclear program.

The UN Security Council, meeting in emergency session to discuss the crisis, should condemn the crackdown and consider temporary sanctions including an arms embargo and protection for Libyan civilian population centers.

"United Nations leadership is on the line. Libya's mission to the UN bravely condemned their own government. Now UN action is critical," said Kerry, who urged a special UN human rights probe and emergency humanitarian aid.

The senator also urged the Arab League and African Union to take a stand, stressing: "American credibility was on the line with a key ally in Egypt, and President Obama acted with determination."

"The Arab League can demonstrate that after the popular uprisings across the region, the old rules of impunity no longer stand. And the African Union can vigorously investigate reports that African mercenaries are involved in the atrocities in Libya," said Kerry.

"These are concrete steps that must be taken now and in the days ahead to show that the world will respond with actions not just words when a regime wields reprehensible violence against its own people," said the senator.