The International Air Transport Association (IATA) said the COVID-19 testing requirements and other measures for travellers from China have proven ineffective and called for governments to base their decisions on "science facts" rather than "science politics".

"Several countries are introducing COVID-19 testing and other measures for travellers from China, even though the virus is already circulating widely within their borders. It is extremely disappointing to see this knee-jerk reinstatement of measures that have proven ineffective over the last three years," Willie Walsh, IATA Director General, said in a statement released on Wednesday.

Research undertaken around the arrival of the Omicron variant concluded that putting barriers in the way of travel made no difference to the peak spread of infections. At most, restrictions delayed that peak by a few days. If a new variant emerges in any part of the world, the same situation would be expected, he said.

"That's why governments should listen to the advice of experts, including the WHO, that advise against travel restrictions. We have the tools to manage COVID-19 without resorting to ineffective measures that cut off international connectivity, damage economies and destroy jobs. Governments must base their decisions on 'science facts' rather than 'science politics'," Walsh said.

The IATA is a large international trade association for world's airlines. It has about 300 member airlines across the world, comprising 83 percent of total air traffic of the world.

China announced in late December it was downgrading its management of COVID-19 from Class A to Class B. As a major change to the country's antivirus strategy, the downgrade will ease restrictions for inbound travellers, and they will no longer have to undergo quarantine or take a nucleic acid test upon arrival in China, starting Jan 8.