DOL

Department of Labor.  Hiring foreign workers for employment in the U.S. normally requires approval from several government agencies.  First, employers must seek labor certification through the U.S. Department of Labor (DOL).  Once the application is certified (approved), the employer must petition the U.S. Citizenship and Immigration Services (USCIS) for approval of the petition before applying for a visa.

Source: U.S. Department of State.