President Reagan joined with President Mobutu Sese Seko of Zaire in offering praise Thursday for Jonas Savimbi, the guerrilla leader trying to overthrow Angola's communist government, the White House said. During their 15-minute White House meeting, the two presidents also thanked each other for backing solutions to problems in southern Africa and Angola, where the United States has been pressing for the pullout of pro-government Cuban military forces, said White House spokesman Marlin Fitzwater. The White House issued a statement later Thursday saying Reagan and Mobuto agreed to support the goal of independence for South Africa-controlled Namibia and peace and reconciliation between the Angolan government and the UNITA guerrillas in Angola. Accusations that Zaire tortures prisoners and commits other human rights abuses were not raised at the White House session, Fitzwater said. The accusations were disputed by Mobutu in a brief talk with reporters. ``You can only oppress a people if they do not have confidence in you, which is not the case in Zaire, contrary to what has been written,'' he said. Mobutu, on a private visit to the United States, said the main purpose of his White House call was to thank Reagan ``for all he has done for Zaire in the framework of the friendship and solidarity which exists between our two countries.'' He also congratulated Reagan ``for the successes he had during the Moscow summit .. he has given a glimmer of hope to all of humanity.'' The Zairean president was also meeting with U.S. Treasury Secretary James Banker and with officials of the World Bank, which last year granted his country an $80 million loan.