sentences:  Mandela rejected all concessions to the South African government, which he accused of seeking the easing of sanctions before it had offered "profound and irreversible change".Mandela delayed meeting Thatcher until he had gathered support for sanctions from other world leaders in the course of a four-week, 14-nation tour of Europe and the United States.Their first meeting failed to resolve differences over her unilateral lifting of sanctions and his refusal to renounce armed struggle until existing conditions for the black majority in South Africa changed.