The Treasury Department designated Libyan Foreign Minister Moussa Koussa and 16 major entities owned or controlled by the Government of Libya. The effort is an attempt to isolate Libyan officials, as the government's forces crush Libyan rebels that had conquered large portions of the country.

The move freezes any U.S.-based asset of those designated, and makes it illegal for people in the United States to do business with them. The other entities targeted are part of Libya's banking, oil, aviation and investment sectors. Officials say they want to use some of the $32 million in frozen assets to help Libyan rebels. The U.S. has been more cautious about imposing a French-led no-fly zone over the North African country, a move supported by the Arab League and a strong rebel demand repeated in a meeting with Secretary of State Hillary Clinton.

U.S. officials nevertheless touted the action as a "strong" step against Libyan government finances. "Today's designation of Moussa Koussa builds on the strong steps taken by the United States to apply targeted, financial pressure on the Qadhafi regime," said Acting Under Secretary for Terrorism and Financial Intelligence David S. Cohen. "The identification of state-owned companies furthers Libya's isolation from the U.S. financial system."

In continued fighting in Libya Tuesday, rebels lost the important town Ajdabiya along the coast to government advances, while the control of the rebel-held port of Brega remains contested. The frontline of their force is being pushed back in the direction of the rebel capital, Benghazi, as Muammar Gaddafi's forces bombard eastern cities from the air, land, and sea. U.S. officials "understand the urgency of this," Clinton said, and are looking for ways to support the opposition.