Secretary of State Hillary Clinton to visit Angola on Sunday . African country is major supplier of petroleum , liquefied natural gas to U.S. market . The United States has been trying for years to get the Angolan government and its allies in neighboring countries to end their support for rebel groups fighting against Mobutu Sese Seko's regime.
Secretary of State Hillary Clinton to visit Angola on Sunday . African country is major supplier of petroleum , liquefied natural gas to U.S. market . Clinton to visit seven African nations in 11 days .