Prime Minister David Cameron said on Monday that Britain would work with allies on plans to enforce a no-fly zone in Libya to protect its people from military attacks by Muammar Gaddafi's government.
Speaking to parliament, Cameron urged Gaddafi to step down and said that all measures would be considered to increase pressure on him to go.
"We do not in any way rule out the use of military assets," Cameron said.
"We must not tolerate this regime using military force against its own people. In that context I have asked the Ministry of Defense and the Chief of the Defense Staff to work with our allies on plans for a military no-fly zone."
Separately, the U.S. military is repositioning naval and air forces around Libya, a Pentagon official said on Monday.
"We have planners working and various contingency plans and I think it's safe to say as part of that we're repositioning forces to be able to provide for that flexibility once decisions are made ... to be able to provide options and flexibility," said Colonel David Lapan, a Pentagon spokesman.
United States and European officials had discussed plans to impose a no-fly zone over Libya to prevent further killings of civilians by troops loyal Gaddafi, The New York Times reported on Monday.
The newspaper cited an unnamed senior administration official as saying that no decision had been made.
Italian Foreign Minister Franco Frattini said Sunday that a key friendship treaty signed between Italy and Libya in 2008 was "de facto suspended."
"When the head of a regime shoots his own people the international community has to react and it has reacted," he said after the approval of U.N. sanctions.
Asked about the possibility of imposing a no-fly zone in Libya, Frattini said: "It's an option that would constitute a real escalation of a military-type intervention. We need time to reflect on it."
The friendship treaty between Italy and Libya opened the way to billions of euros (dollars) in investment deals between the two countries and imposed a harsh crackdown on illegal immigration toward Italian shores.
The Times said the accord also contains a non-aggression clause that some analysts said complicated Italy’s position in the event of international military intervention in Libya.
According to The Times, imposing a no-fly zone would require further debate among the 15 nations on the Security Council, which was unlikely to act unless there was a significant increase in state-sponsored violence in Libya, including the use of aircraft against civilians.
U.N. Secretary General Ban Ki-moon was scheduled to meet with President Barack Obama on Monday at the White House to discuss the deteriorating situation in Libya.
Obama administration officials said Sunday that they were also discussing whether the U.S. military could disrupt communications to prevent Colonel Gaddafi from broadcasting in Libya, the paper said.
In addition, the administration was looking at whether the military could be used to set up a corridor in neighboring Tunisia or Egypt to assist refugees, the report said.
There are several United States and NATO bases in Italy that presumably would be staging areas for any action against Libya, including the United States Sixth Fleet base near Naples, the paper said.