U.S. Defense Secretary Robert Gates has decried what he called "loose talk" about establishing a no-fly zone in Libya, saying such an operation would require a military strike.
Speaking to a U.S. congressional committee Wednesday, Gates said establishing an area where U.S. planes could fly safely would require first destroying Libya's air defense forces. He called it a "big operation in a big country."
Secretary of State Hillary Clinton has said Washington and its NATO allies were considering establishing a no-fly zone over Libya to prevent forces loyal to Libyan leader Moammar Gadhafi from carrying out more attacks on opposition forces.
Clinton told a Senate committee Wednesday that the U.S. is still "a long way from making that decision."
The U.S. Senate unanimously adopted a resolution Tuesday calling on the U.N. Security Council to consider setting up a no-fly zone.
Meantime, two U.S. amphibious assault ships have entered Egypt's Suez Canal on the way to waters off Libya, to provide emergency evacuations or humanitarian relief as necessary.
Canal officials say the USS Ponce and the USS Kearsarge entered the waterway's southern mouth Wednesday morning local time and were expected to exit into the Mediterranean by the evening.
The U.S. ambassador to the United Nations, Susan Rice, said Washington will maintain military, economic and political pressure on Mr. Gadhafi until he steps down and allows the Libyan people to express themselves freely.
Some information for this report was provided by AP, AFP and Reuters.