But the U.S. showed caution, warning against a go-it-alone approach.

"Absent international authorization, the United States acting alone would be stepping into a situation whose consequences are unforeseeable," Clinton said. "We're looking to see whether there is any willingness in the international community to provide any authorization for further steps."
Clinton said the U.S. was suspending its relationship with Libya's remaining envoys to the country, although the move falls short of severing diplomatic relations. She said she would meet with Libyan opposition figures when she travels to Egypt and Tunisia next week, marking the highest level contact between the U.S. and the anti-Gadhafi elements.
NATO said it had started round-the-clock surveillance of Libyan airspace, and British Foreign Secretary William Hague said a meeting of EU foreign ministers would discuss how to isolate the regime.
U.N. Ambassador Maged Abdelaziz of Egypt expressed serious concern about the more than 1 million Egyptians still in Libya, "and we are afraid that the tragic events that happened in Iraq using human shields to protect air defense systems on the ground would be repeated." He added that he had "no concrete information" about whether that was happening.
Germany said it froze billions in assets of the Libyan Central Bank and other state-run agencies. The U.S., Britain, Switzerland, Austria and other countries have also frozen Gadhafi's assets.
"The brutal suppression of the Libyan freedom movement can now no longer be financed from funds that are in German banks," Economy Minister Rainer Bruederle said.
The Libyan government tried to stave off tough action, sending envoys to Egypt, Portugal and Greece. Associated Press writers Maggie Michael in Tripoli; Zeina Karam in Cairo; John Heilprin in Geneva; Elaine Ganley in Paris; Edith M. Lederer at the United Nations; Don Melvin and Robert Burns in Brussels; Bradley Klapper and AP White House Correspondent Ben Feller in Washington; and Alan Clendenning in Madrid contributed to this report.