Southern African countries meeting on Sunday in Cape Town have vowed to lobby hard for South Africa's Nkosazana Dlamini-Zuma to be elected new African Union chief in fresh polls after a recent deadlock.

The 15-member Southern African Development Community (SADC) again backed the former foreign minister in a two-day meeting called to plot the bloc's strategy after she failed to unseat Gabon's Jean Ping as chair of the AU commission nearly two weeks ago.

"It's going to be a campaign of all SADC member states and we are going to work and convince others with all the strong arguments that we have," Angolan Foreign Minister Rebelo Pinto Chikoti told a gala dinner on Saturday.

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

Chikoti said it was southern Africa's opportunity to have the AU's top post, but that the tightly contested race -- seen as exposing divides between geographical regions and French- and English-speaking Africa -- was not a 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 was the first woman to be proposed by SADC as an AU head and Chikoti praised her leadership, saying the bloc believed it had a "very good candidate".

Last month's tightly contested AU race saw Ping, who has headed the AU's executive arm since 2008, 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 campaigns, with Ping counting on support from French-speaking West and Central African countries, and Pretoria lobbying across Africa for Dlamini-Zuma.