Southern African countries have vowed to lobby hard for Nkosazana Dlamini-Zuma to be elected African Union chief after a recent poll deadlock.

The Southern African Development Community reiterated its support for South Africa's home affairs minister at a two-day meeting in Cape Town called to plot the bloc's strategy after she failed to unseat Gabon's Jean Ping as chairman of the AU Commission nearly two weeks ago.

Angolan Foreign Minister Rebelo Pinto Chikoti said at an AU dinner on Saturday: "It's going to be a campaign of all SADC member states and we are going to work and convince others with strong arguments.

"All other regions have had this position [chairman] and, through democratic processes, we have worked with them, so what we ask them this time is for them to allow us this chance."

Chikoti said the tightly contested race for the top AU post - seen as exposing divisions between geographical regions and French- and English-speaking Africa - was not rivalry.

"We are not doing this as a fight against anybody; we are not making a fight against people or even against our dear partners," he said.

Dlamini-Zuma is the first woman to be proposed by the SADC as an AU head.

Chikoti praised her leadership, saying the bloc believed it had a "very good candidate".

Last month, Ping, who has headed the AU's executive arm since 2008, was unable to obtain the required two-thirds majority of African leaders' votes in a tight race with Dlamini-Zuma.

The AU extended Ping's mandate until its next summit, scheduled for June in Malawi.

The vote was preceded by intense lobbying, with Ping counting on support from French-speaking west and central African countries, and Pretoria lobbying across Africa for Dlamini-Zuma.