Pierre Korkie, pictured, was a teacher at Grey College in Bloemfontein and Yolande a preprimary teacher.

Johannesburg - The wife of the man being held in Yemen pleaded on Thursday for his release as the kidnappers' deadline for his ransom approached.

Yolande Korkie, wife of Pierre Korkie, appeared gaunt and frail as she read a statement to reporters in Johannesburg.

"Al-Qaeda, I ask to address you. Thank you for releasing me and giving me back to our children, treating us with kindness and respect and bringing my husband medicine."

Speaking softly because of a throat infection, she added: "I'm asking you to release my husband."

Korkie, wearing pants with a flowery top, described Pierre as a humble and gentle man.

The couple, who have been married for 20 years, was abducted in the city of Taiz, in Yemen, in May.

Pierre had been teaching in Yemen while Yolande worked in hospitals helping with relief work.

On Friday, the kidnappers demanded payment of US3 million (about R32.5m) within eight days to secure Korkie's release.

Negotiations had not been going well, said Imtiaz Sooliman, head of the Gift of the Givers Foundation, which negotiated Yolande's release last week.

Sooliman said the captors had been asked for another month, and Al-Qaeda's response was being awaited.

Yolande, referring to the fable of the Queen of Sheba and King Solomon, said the Yemeni people were gold.

"No one told us we would fall in love with the people," she said.

She reminded the kidnappers of the forgiveness former president Nelson Mandela had been preaching.

"We are asking you to show mercy, to please show tolerance."

Sooliman said: "There is no merit in harming him."

He said a South African flag was placed behind Yolande at the press conference to emphasise that she and her husband were South Africans.

Gift of the Givers Yemen office manager Anas al-Hamati started face-to-face talks with the kidnappers, linked to Al-Qaeda, on Monday night.

"While Anas was with them, the Al-Qaeda guys called me and asked what's the problem. I said there's no money, the price is too high, and the time is too short," Sooliman said at the time.

"Anas discussed the same points. They kept on saying if we don't have the money by Friday it will be the end for Pierre."

Yolande arrived back in South Africa on Monday afternoon.