Libyan leader Muammar Gaddafi has a better chance of retaining power the longer the conflict drags out, but it remains possible the rebel stronghold in the eastern part of the country could emerge as a "mini-state", a top US intelligence official has said.
Gaddafi's forces are better equipped "from a standpoint of attrition" to outlast the rebels in a stalemate, and under such a scenario "the regime will prevail", National Intelligence Director James Clapper said on Thursday.
But he cautioned developments in Libya are "very fluid" and "hard to assess".
"You could end up with a situation where Gaddafi would have Tripoli and its environs and then (the rebel stronghold of) Benghazi and its environs could be under another mini-state," he told the Senate Armed Services Committee.
The head of the Pentagon's intelligence agency, Lt. Gen. Ronald L. Burgess, said at the same hearing that the momentum has shifted to Gaddafi.
"Whether or not it has fully moved to Gaddafi's side at this time... is not clear at this time," he said. "But we have now reached a state of equilibrium where the initiative, if you will, may actually be on the regime side at this time."
US President Barack Obama has called on Gaddafi to leave power and his administration has sought ways to apply pressure working with the international community. The US has frozen more than $30 billion in assets belonging to Gaddafi's government, and the European Union has also enacted sanctions on the 41-year-old regime.
US Secretary of State Hillary Rodham Clinton said the US is suspending "existing ties" with the Libyan embassy in Washington. "We expect them to end operating as the embassy of Libya," she told a House committee.
The US was in discussions with UN, NATO, the African Union and Arab League to further isolate Gaddafi with sanctions to pressure him to stop the "horrific" attacks on his people, Clinton said.
"We're looking to see whether there is any willingness in the international community to provide any authorization for further steps," she said.
The US was keeping military options open, including a possible no-fly zone, but will not act without the consensus of the international community because such a move would have "unforeseeable" consequences.
"Absent international authorization, the United States acting alone would be stepping into a situation whose consequences are unforeseeable," Clinton said. "And I know that's the way our military feels."
Clinton said the US has been reaching out to Libya's opposition and will continue to do so when she travels to Egypt and Tunisia next week.
NATO decided at a meeting of defence ministers in Brussels to move warships into Libya's vicinity but would not launch any attacks without the explicit backing of the UN Security Council.
NATO already has AWACS radar aircraft monitoring Libyan airspace, but defence ministers at a long-planned meeting Thursday agreed that the alliance needs to beef up its monitoring of the country's coast.
"It has been decided to increase the presence of NATO maritime assets in the central Mediterranean," NATO Secretary General Anders Fogh Rasmussen told journalists.