The World Health Organisation's (WHO) top emergency expert has said that it was important for all countries to have “consistent messaging” for their public, following contradictory remarks by President Donald Trump and US health officials, Reuters reported.

“It is important that we have consistent messaging from all levels, and it's not for one country or one entity; consistent messaging between science and between government,” WHO's Mike Ryan said in response to a question at an event marking World Patient Safety Day.

“What is important is that governments, scientific institutions, step back, review the evidence, and give the most comprehensive easy-to-understand-and-digest information so that people can take the appropriate action,” Ryan said.

“It's understanding the confusion, it's understanding their concern, it's understanding their apprehension. And not laughing at it and not turning that into some kind of political football.”