GENEVA — The U.S. repositioned some naval forces near Libya and threatened Monday that all options remain on the table to protect Libyans threatened by an increasingly isolated and defiant Moammar Gadhafi, including the possible use of warplanes to patrol Libyan skies.

Secretary of State Hillary Rodham Clinton said the United States is exploring the idea of a no-fly zone to prevent Gadhafi’s regime from bombing its citizens, and she welcomed a series of sanctions outlined by European leaders designed to force the dictator to stop attacks on civilians and step down after 42 years of iron-fisted rule.

After a series of meetings with foreign policy chiefs in Switzerland, Clinton said the United States is sending aid teams to help Libyan refugees. She sharpened the U.S. demand that Gadhafi step aside in the face of armed opposition now in control of large portions of the North African oil state.

“Gadhafi has lost the legitimacy to govern and it is time for him to go without further violence or delay,” she said.

“No option is off the table. That of course includes a no-fly zone,” Clinton added.

The European Union issued travel bans and an asset freeze against senior Libyan officials, and an arms embargo on the country. Germany went further, proposing a 60-day economic embargo to prevent Gadhafi’s regime from using oil and other revenues to repress his people.

Meanwhile, the Pentagon said Monday that it was moving naval and air forces in the region in case they are needed, but did not say what they might be used for.

“We have planners working various contingency plans and … as part of that we are repositioning forces in the region to be able to provide options and flexibility,” said Marine Col. Dave Lapan, a Defense Department spokesman.

Describing the Pentagon as in “preparing and planning mode,” Lapan said the U.S. military is not involved in the planned French humanitarian flights and that no decision had been made on whether to set up a no-fly zone. He declined to say whether the U.S. had flown surveillance and intelligence flights over Libya.

The U.S. has a regular military presence in the Mediterranean Sea, two aircraft carriers in the Persian Gulf area and a wide range of surveillance equipment available for use in the region. Without specific information about what assets are being moved and where, it is impossible to tell whether the U.S. was issuing a largely empty threat.

Clinton said the flight ban is under active consideration by the U.S. and its allies, but the idea seemed far-fetched for now. Senior U.S. officials said the issue was not even discussed during Clinton’s meeting with Russian Foreign Minister Sergey Lavrov, whose OK would be important. Lavrov dismissed the idea in remarks following his meeting.

Clinton said the U.S. will send special aid teams to Libya’s borders with Egypt and Tunisia, where increasingly desperate crowds are fleeing a potential civil war. She said the U.S. has pledged $10 million to help refugees.

EU foreign policy chief Catherine Ashton said the European measures, including a freeze on assets, aim to reinforce U.N. Security Council sanctions against Libya approved over the weekend.

The EU action is significant because Europe has much more leverage over Libya than the United States — 85 percent of Libyan oil goes to Europe,l and Gadhafi and his family are thought to have significant assets in Britain, Switzerland and Italy. Switzerland and Britain already have hit Libya with a freeze on assets.

Even before Ashton announced the new sanctions, France pledged to send two planes with humanitarian aid to Libya’s opposition stronghold of Benghazi while Germany also mulled a two-month cutoff of oil payments to Gadhafi’s regime. This came after days of increasing concern about the hundreds, and potentially thousands, of deaths caused by Gadhafi’s military resistance against the popular uprising in his country.

“The massive violence against peaceful demonstrators shocks our conscience. It should also spring us into action,” Ashton told the Human Rights Council.

The EU also embargoed any equipment that could be “used for internal repression,” Ashton said, urging nations to coordinate actions to help people across North Africa and the Middle East.

She said the possibility of creating a no-fly zone over Libya would involve a more complex set of negotiations.

British Prime Minister David Cameron told British lawmakers Monday he is working with Britain’s allies on a plan to establish a military no-fly zone over Libya, since “we do not in any way rule out the use of military assets” to deal with Gadhafi’s embattled regime.

In Paris, French Prime Minister Francois Fillon said many more discussions were needed before the United Nations would support a no-fly zone over Libya and questioned whether NATO should get involved in a civil war in a North African country. The NATO chief has already rejected intervening in Libya.

Libya’s oil chief says production is down 50 percent due to foreign oil workers fleeing the uprising, but the head of the National Oil Co. told The Associated Press on Monday that Libya’s oil installations are protected and safe, disputing remarks by the EU energy commissioner who said Gadhafi has lost control of major fields.

The EU gets almost 5 percent of its fuel from Libya, which has the largest proven oil reserves in Africa, ahead of even Nigeria and Algeria. In 2009, the EU imported $27.5 billion in fuel from Libya — accounting for 85 percent of all the $32 billion in fuel that Libya exported that year, according to World Trade Organization figures.

Gadhafi’s government has been in power since 1969, but Clinton told the U.N.’s Human Rights Council that he and his allies have “lost the legitimacy to govern” by reportedly executing soldiers who refused to turn their guns on civilians and other severe human rights abuses. The council itself has recommended suspending Libya as a member.

Fillon said planes were taking off for the eastern city of Benghazi with doctors, nurses, medicines and medical equipment.

“It will be the beginning of a massive operation of humanitarian support for the populations of liberated territories,” he said on RTL radio. “(France is studying) all the options to make Colonel Gadhafi understand that he should go.”

Germany’s foreign minister, Guido Westerwelle, said the EU should consider a total ban on payments to Libya, including for oil deliveries from there. But he said Germany wants a 60-day ban to prevent Gadhafi and his family from receiving any fresh funds.

“This dictator family has to be financially dried up to stop them from hiring ever more mercenaries for a lot of money so they can attack the Libyan people,” Westerwelle told reporters in Geneva. “We must do everything so this murder ends.”

Since the U.N. Security Council voted Saturday to impose new penalties against Libya, Clinton said the United States was “reaching out to many different Libyans who are attempting to organize,” mostly in eastern Libya.

In response Monday, Libya’s state-run news agency, JANA, quoted a foreign ministry official as saying that Clinton’s comments are “a flagrant intervention in Libya’s internal affairs and … of the United Nations charter.”

Australian Foreign Minister Kevin Rudd called on the world’s powers to impose a no-fly zone over Libya and compared Gadhafi’s violent suppression of opposition forces to genocides in Rwanda, the Bosnian town of Srebrenica and Sudan’s Darfur region.

“For the sake of humanity, go now,” Rudd said.

British and German military planes swooped into Libya’s desert over the weekend, rescuing hundreds of oil workers and civilians stranded at remote sites. The secret military missions signaled the readiness of Western nations to disregard Libya’s territorial integrity when it comes to the safety of their citizens.

The U.N. Security Council has told the International Criminal Court to look into possible crimes against humanity occurring in Libya, only the second such referral. The first was in 2005 when the U.N. asked the world’s first permanent war crimes tribunal to probe mass killings in Darfur.