THE United States Embassy in Georgetown yesterday advised that, effective  February 1, 2013, individuals who are issued U.S. immigrant visas outside of the United States must pay a new US$165  USCIS Immigrant Fee, in addition to existing processing fees, before traveling to the United States.  Orphans (visa category IR-3 and IR-4), Returning Residents (visa category SB-1), and individuals who are issued fiancé/e visas (visa category K) are exempt from the new fee.  
The website of the U.S. Citizenship and Immigration Service (USCIS) www.USCIS.gov/immigrantfee provides details about the new fee, including contact information for USCIS.