Travellers from China and Australia's state of Victoria will be allowed to fly into Singapore from next Friday without the need for quarantine, provided they pass a Covid-19 test on arrival.

The unilateral move comes as the Republic continues to ease its border restrictions cautiously and does not change the curbs imposed in China and Australia on travellers from Singapore.

For example, tourists from the Republic are not allowed into the two countries.

The move is significant for Singapore and its aviation sector, Transport Minister Ong Ye Kung told The Straits Times in an exclusive interview yesterday.

Before the pandemic, China was one of Changi Airport's major markets, making up 10.7 per cent of its total traffic last year.

Singapore already has similar arrangements for travellers from Brunei, New Zealand, Vietnam and all other parts of Australia.

The Republic also has reciprocal green lanes for essential business and official travel with several countries including Malaysia, Indonesia and Germany. The scheme requires travellers to follow a controlled itinerary and be sponsored by companies here.

An air travel bubble with Hong Kong that will allow leisure travellers from both sides to visit without the need to be quarantined is expected to take off next month.

The Civil Aviation Authority of Singapore said China and Victoria have comprehensive public health surveillance systems and have successfully controlled the spread of the Covid-19 virus.

Mr Ong said that while he does not expect the number of visitors from China and Victoria to be high, the easing is significant.

"If you cut off air connection, we are strangled," he warned.

Addressing concerns that reopening the borders increases the risk of importing Covid-19 cases, Mr Ong noted that so far, about 600 travellers have come in through the unilateral air travel arrangements. None has tested positive upon arrival.

Still, Singapore is careful about who to lift the barrier for and takes a "hard-nosed assessment" of the virus control measures and their effectiveness in other countries and places.

"I look at the top line (case numbers) every day," Mr Ong said.

But even that is not good enough, he stressed, because the numbers also depend on how much testing is done. "So, we listen to our healthcare professionals in MOH (Ministry of Health), and they do a very thorough assessment of the whole epidemic response in these places," he said.

Asked about Singapore's reciprocal green lane agreements with Germany and Indonesia, where the number of Covid-19 cases remains high, Mr Ong noted that the scheme is limited to business and official travellers, and comes with restrictions.

"They go about their business through a controlled itinerary, they cannot run around, go to hawker centres or take a roller-coaster ride at Universal Studios... We really manage the risk," he said.

Airport workers who come into close contact with travellers will be required to don full-body personal protective equipment, which includes goggles, gloves and gowns, Mr Ong said.

They also have to take a Covid-19 test every two weeks, with about 2,500 who have already undergone the first round of testing reporting negative results.

The stepped-up measures come after two airport workers at Changi's Terminal 3 tested positive for the virus recently, said the minister.