Arab countries appealed to the United Nations on Saturday to impose a no-fly zone on Libya as government troops backed by warplanes fought to drive rebels from remaining strongholds in western Libya.
Washington, which would play a leading role in enforcing any no-fly zone, called the declaration an "important step"; but it stopped short of commitment to any military action and made no proposal for a swift meeting of the U.N. Security Council.

http://news.yahoo.com/s/nm/20110312/wl_nm/us_libya