Angola's President, Jose Eduardo dos Santos, cut a red ribbon to inaugurate the mission and served champagne with words of hope and reconciliation after years of war.
'This ushers in a new era,' said Mr dos Santos on his first visit to South Africa to pay respects to the new President and long-time ally, Nelson Mandela.
'In the past we had very conflictive relations. We want to overcome that phase and establish secure bases of co-operation.' Mr dos Santos told reporters he expected the end of three centuries of white domination in South Africa after last month's elections to have a stabilising role in the region which would favour peace.
The ANC has close links with Angola's ruling MPLA (Popular Movement for the Liberation of Angola), which sheltered and provided training camps for ANC guerrillas after it came to power upon independence from Portugal in 1975.
South Africa's former white rulers supported Unita rebels during 16 years of civil war which ended briefly with 1991 peace accords.