Freshly elected Chinese President Xi Jinping is finally about to unveil his secret weapon to rock international diplomacy: his singer wife Peng Liyuan.

Since Xi's appointment as the Communist Party's general secretary in November, Peng has remained in the shade, an unusual place for the 50-year-old folk singer, who is a hugely popular figure in China.

The Chinese have been eagerly waiting their first joint public appearance, but for the disappointment of many this will reportedly take place overseas, as Xi intends to use his wife's charm to help build diplomatic bridges and foster China's shaking appeal abroad.

Confirmed as president by China's rubber-stamp Parliament this week, Xi will be flying to Moscow and then to South Africa in his first official overseas visits later this month, reportedly accompanied by Peng, whom he married in 1987 after his first marriage ended in divorce.

"She can help China built soft power," a source close to the president told the Financial Times.

"She will win over hearts with her warm personality," a friend of the glass-cracking soprano told the British newspaper.

Since Xi was appointed Vice president in 2008, Peng has lowered her profile, quitting all public performances in line with Chinese first ladies' habit of standing quiet behind their prominent husbands.

The rule has been observed since Madame Mao, Jiang Qing, was purged and arrested during the violence and chaos that followed Mao's Cultural Revolution.

However Peng seems poised to break with tradition.

Having dropped her regular TV appearances on China Central Television's Lunar New Year variety show, she has dedicated herself to charity work. She provided testimonials for anti-smoking and safe-sex campaigns and in 2011 became a goodwill ambassador for the United Nations World Health Organisation.

She also holds the equivalent of a major general's rank in the People's Liberation Army, and in fact was the youngest civilian ever to receive the distinction.

Commentators believe Peng could boost her husband's popularity just as iconic first ladies such as Jacqueline Kennedy and Raisa Gorbachov have done in the past.

"Peng Liyuan could be an enormously positive thing for China, which really needs female role models," Hung Huang, publisher of a fashion magazine told the New York Times.

"Just imagine if she turned out to be a first lady like Michelle Obama."