Updated

WASHINGTON -- The U.S. renewed efforts Wednesday to evacuate American citizens from Libya, this time by ferry, as concerns rise about longtime leader Moammar Gadhafi's unpredictable behavior.

As security forces unleashed a bloody crackdown on protesters demanding Gadhafi's ouster, Secretary of State Hillary Rodham Clinton called the violence "completely unacceptable."

"We believe that the government of Libya bears responsibility for what is occurring and must take actions to end the violence," Clinton said Tuesday.

But as it sought to safely extricate U.S. diplomats and other Americans from the spreading chaos, the Obama administration stopped short of criticizing Gadhafi personally or demanding that he step down. U.S. officials who spoke to the matter publicly on Tuesday, including Clinton, would not mention Gadhafi by name.

Unease over the safety of U.S. citizens intensified after attempts to get some out on Monday and Tuesday were unsuccessful. Late Tuesday, the State Department announced that American citizens would be evacuated from Libya by ferry to the Mediterranean island of Malta.

On Wednesday morning, officials were processing U.S. citizens for the ferry trip from Tripoli's As-shahab port.

The mercurial Gadhafi -- once termed the "mad dog of the Middle East" by President Ronald Reagan -- has long flummoxed U.S. officials. He is notoriously unpredictable and has been known to fly into rages at real or perceived slights.

The Obama administration did not outline any specific steps to coerce or punish the Libyan regime, with which the U.S. has built a wary partnership after years of branding Gadhafi a terrorist sponsor. After decades of hostility, the U.S. and Libya normalized ties during President George W. Bush's presidency after Gadhafi renounced terrorism and weapons of mass destruction but relations have been far from fully cordial.

U.S. officials said Washington would join other nations to address Libyan behavior at the U.N. Security Council. They renewed calls for Gadhafi's government to talk with opponents, and cast the political unrest there as part of a regional uprising against political and economic stagnation that must be addressed by the Arab governments of the Middle East and North Africa.

Gadhafi delivered a defiant speech on national television in which he vowed he will not step aside. He said he would die a martyr's death fighting those rebelling against his 42-year-old rule. The address was filled with references to his standing up to the United States and other world powers and threats to execute protesters.

In addition to the tone, the speech unnerved U.S. officials because it was delivered in front of the rubble of the Tripoli compound that the U.S. bombed in 1986, killing Gadhafi's young daughter. As he spoke state-run television repeatedly showed a courtyard statue of a clenched fist crushing a U.S. fighter jet.

With the potential for Gadhafi to foment anti-American or anti-western sentiment and Libya teetering on the brink of what some fear will explode into a full-blown civil war, administration officials repeatedly invoked their primary concern of ensuring the safety of U.S. citizens there.

"As always, the safety and well-being of Americans has to be our highest priority. We are in touch with many Libyan officials directly and indirectly and with other governments in the region to try to influence what is going on inside Libya," Clinton told reporters at the State Department.

Department spokesman P.J. Crowley said U.S. officials had been assured by Libyan authorities that embassy workers and families will be able to leave safely. He said the United States expected those pledges to be honored.

"They've pledged to support us in our evacuation, and we hope that cooperation will be forthcoming," he said.

Crowley said the department was trying to get 35 nonessential staff and family members of personnel at the U.S. Embassy in Libya out of the country. The State Department ordered them to leave Monday but they have not yet been able to depart, he said without elaborating on the reason.

The department also believes there are several thousand dual U.S.-Libyan nationals and about 600 private U.S. citizens in Libya. Crowley said the U.S. was working with other countries and airlines to increase the capacity of commercial flights and was also prepared to charter planes if necessary. But he noted that would require Libyan consent.