A hotly-anticipated air travel bubble between Singapore and Hong Kong has been delayed until next year, the cities' authorities said on Tuesday, due to a spike in coronavirus cases in Hong Kong.

The first flights between the two Asian financial hubs were called off a day before they were due to depart on November 22. 

If they had gone ahead it would have been the first quarantine-free travel bubble in Asia.

The Civil Aviation Authority of Singapore said in a statement there would be a review in late December over when to proceed.