Mr Wang, 51, now on an African tour, is a veteran Asian affairs expert, especially on North Korean and Japanese issues.

As a fluent Japanese speaker, having served in the Chinese embassy in Japan from 1989-94, he was expected to be appointed ambassador three years ago during the last change in the post, sources said. But to the surprise of Japan, the then ambassador in Seoul, Wu Dawei , got the job.

'He is definitely the best candidate for the post because he speaks the language and can communicate with the Japanese directly. For instance, he has a good personal relationship with the head of the Japanese delegation during the six-party talks on North Korea,' one of the sources said.

But Mr Wang had been tipped as a strong contender to become the next foreign minister, the sources noted.

Bilateral relations have soured over the disputed Diaoyu Islands, Japanese Prime Minister Junichiro Koizumi's repeated visits to the Yasukuni war shrine in Tokyo and growing conflict over oil and gas resources.

The discord surrounding these issues has even spilled over into some traditionally trouble-free areas, such as economic ties and cultural and sports exchanges, which were protected previously by mutual interest.

The ugly aftermath of China's 3-1 loss to Japan in the Asian Cup soccer final early this month in Beijing plunged bumpy relations to a new low.

Mr Wang's appointment is also believed to be part of a warm-up for his future promotion.

The appointment may surprise some people; he had been widely tipped early this year to be the next ambassador to Canada.

In 1977 Mr Wang, a native of Beijing, was admitted to the Beijing International Studies University, established by premier Zhou Enlai 50 years ago for the training of diplomatic personnel.

During his college days, Mr Wang excelled while majoring in Japanese and impressed his fellow students with his keen interest in domestic and international affairs and a variety of hobbies, according to an article published by a magazine in the Nanfang Daily group.

Classmate Wang Xiaoping , a lawyer in Beijing, said: 'He was held up by the Cultural Revolution for quite a long time [when he worked for eight years before entering university]. He was good at writing, thanks to his rich experience and mature thinking.'

Mr Wang joined the Foreign Ministry in 1982 and spent the next 15 years in the Asian affairs department until he became one of the youngest assistant ministers in the ministry's history in 1998.

He is known in the ministry for his rapid rise to become deputy minister within 19 years, and his ability and diligence.

He was praised by then Communist Party secretary Hu Yaobang for writing a speech which Hu used during his 1983 trip to Japan.

'It was rare for Foreign Ministry officials to win applause from top leaders, especially from someone like Hu, a well-known nitpicker,' one source said.

Mr Wang is said to have learned English by himself over the years. 'He can communicate with foreign guests in English without interpreters,' said a ministry official.

His relatively smooth career can also be attributed to a policy shift from 1989 when China began to attach more importance to neighbouring countries.

As one of the most senior diplomats in charge of Asian affairs, he and the Asian department appeared to be ever more important, especially during the North Korean nuclear crisis.

Fu Ying , picked by Mr Wang as his successor in charge of the Asian affairs department, serves as another example. Ms Fu became ambassador to Australia in March.

There are some who speculate that Mr Wang's success as a diplomat is mainly due to his father-in-law, Qian Jiadong , a seasoned diplomat who was foreign affairs secretary for Zhou Enlai.

Even those who labelled Mr Wang as one of the princeling party, known as taizidang, cannot easily deny his performance at the six-party talks that has put him in the limelight in the past year.

While being head of the Chinese delegation may have won him international fame, years of hard work have taken their toll on his health.

The sources in Beijing said he had had an operation on a benign pancreatic tumour just before he attended the third round of the talks in June.