They may never have authorized anything as would be necessary for a more escalated conflict, but they certainly supported intervention:

> 1 March 2011: The US Senate unanimously passes non-binding Senate resolution S.RES.85 urging the United Nations Security Council to impose a Libyan no-fly zone and encouraging Gaddafi to step down. The US had naval forces positioned off the coast of Libya, as well as forces already in the region, including the aircraft carrier USS Enterprise.