The ministry has invited Dr Chan to fly to Beijing to discuss her election strategy.

A deputy director-general of the Ministry of Health's department of international co-operation, Ren Minghui said Dr Chan's candidacy was a 'mutual wish' by both the central government and the veteran health official.

'[We are nominating her] because we think China needs to play an active role in global public health,' Mr Ren said, adding that Dr Chan had years of experience in the area, especially in bird flu. 'We are very confident about her ability... and we are confident that she will be elected.'

Mr Ren said he believed Dr Chan's election would be conducive to co-operation between China and the global health agency.

The post of director-general has been vacant since the sudden death of Lee Jong-wook in May.

Beijing's high-profile support for Dr Chan, made in an announcement by the Ministry of Foreign Affairs, came as a surprise to some of WHO's 192 member states. It will put Dr Chan in stiff competition against Japan's Shigeru Omi, the WHO's regional director for the western Pacific, who until yesterday was considered a certainty for the post. The third candidate so far is Mexico's health minister, Julio Frank, who lost to Dr Lee in the last election for the post, in May 2003.

'Dr Chan has profound medical knowledge and rich experience in public health management and has thorough understanding of WHO rules, as well as challenges and opportunities for the global health system,' Foreign Ministry spokesman Liu Jianchao said.

Dr Chan was criticised in the report of the Legislative Council's Sars inquiry for Hong Kong's failure to respond quickly enough in the early days of the Sars outbreak.

The WHO has assumed an increasingly high-profile role in the global fight against infectious illnesses in the wake of successive outbreak of diseases such as Sars and bird flu.

The mainland, known for its lack of transparency in previous outbreaks, is a country the WHO is eager to engage in its global network of member states.

In a phone interview with Cable TV, Dr Chan, who turns 59 next month, said she felt 'glad and very honoured' by China's endorsement of her candidacy.

'There are other candidates who are very experienced in public health. Running any election campaign is never an easy job, but we will try our very best to do it,' she said.

The WHO executive board will decide on its preferred candidate to be put to the World Health Assembly on November 9.