WASHINGTON -- The Obama administration condemned "appalling" violence in Libya, where security forces unleashed a bloody crackdown on protesters demanding the ouster of longtime leader Muammar al-Qaddafi.

"This violence is completely unacceptable," Secretary of State Hillary Rodham Clinton said Tuesday. "We believe that the government of Libya bears responsibility for what is occurring and must take actions to end the violence."

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

Unease over the safety of U.S. citizens intensified after attempts to get some out on Monday and Tuesday were unsuccessful amid concern about Qaddafi's unpredictable behavior, and late Tuesday the State Department announced that American citizens would be evacuated from Libya by ferry to the Mediterranean island of Malta.

In a notice sent to U.S. citizens in Libya, the department said Americans wishing to leave the country should be at the As-shahab port in Tripoli with their passports starting at 9 a.m. local time Wednesday for a departure no later than 3 p.m. local time.

The mercurial Qaddafi -- 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 Qaddafi a terrorist sponsor. After decades of hostility, the U.S. and Libya normalized ties during President George W. Bush's presidency after Qaddafi 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 Qaddafi'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.

Qaddafi 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 Qaddafi'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 Qaddafi 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 on 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.

In January, the U.S. ambassador to Libya, Gene Cretz, was recalled to Washington for consultations amid concerns that his detailed accounting of Qaddafi's eccentricities in secret diplomatic cables published by the website WikiLeaks would compromise his ability to work with the Libyan government. More than a month later, Cretz has yet to return to Libya.

In 2010, Crowley was forced to apologize for a joking remark he made about Qaddafi's rambling speech to the U.N. General Assembly a year earlier. Libya had threatened diplomatic retaliation unless he apologized.

Asked about Qaddafi's fiery speech on Tuesday, Crowley demurred.

"We want to see the bloodshed stopped," he said. "We want to see the government engage its citizens, rather than attack its citizens."

"This is ultimately and fundamentally an issue between the Libyan government, its leader and the Libyan people," Crowley said. "They, like others, are standing up and demanding a greater say in the events of their country. We have grave concerns about the Libyan response to these protesters."

Earlier, White House spokesman Jay Carney called on Qaddafi's regime to respect the universal rights of its citizens and allow peaceful protests to take place. Echoing earlier White House statements about anti-government protests in Egypt, he said the future of Libya needs to be decided by the Libyan people.

Meanwhile, top lawmakers said the U.S. should consider imposing new sanctions on the regime and called for foreign energy companies to immediately shut down operations in the oil-rich North African nation.

Sen. John Kerry, chairman of the Senate Foreign Relations Committee, called the violent crackdown "cowardly" and "beyond despicable." He urged U.S. and international oil companies to immediately suspend their Libyan operations until attacks on civilians stop.

The Massachusetts Democrat also called on the Obama administration to consider re-imposing sanctions against Libya that were lifted by President George W. Bush after Qaddafi renounced terrorism and abandoned development of chemical, biological and nuclear weapons.

Sens. John McCain and Joe Lieberman called for the administration to support a no-fly zone over Libya to prevent air attacks.

Rep. Ileana Ros-Lehtinen, chairwoman of the House Foreign Affairs Committee, also called for the imposition of new sanctions, including asset freezes and travel bans on senior Libyan officials.

"The Libyan regime's widespread attacks on the Libyan people are deplorable, and all responsible for these attacks must be held to account," she said in a statement.