It comes after President Donald Trump gave WHO chief Tedros Adhanom Ghebreyesus a 30-day deadline to make "major changes" - threatening that the US would permanently cut off funding to the organisation.

“For the United States to comprehensively withdraw funding would mean the effectiveness of the WHO - particularly in developing countries, where the virus is yet to have its full impact - would be grossly irresponsible in international humanitarian terms," Mr Rudd told BBC World Service.

"Remember in various of these countries the WHO goes in and advises and/or provides direct material help and the setting up of health systems to deal with the crisis on the ground.”

In a tweet, Mr Trump published his full letter to Dr Tedros, in which he criticised the WHO for not doing enough, saying it "consistently ignored credible reports of the virus spreading" late last year in Wuhan.