Italy has joined Iran, China and South Korea as countries to avoid due to coronavirus after Prime Minister Scott Morrison announced that all Australians returning from the European nation would have to undergo quarantine for 14 days.

A worsening of Italy's COVID-19 situation this week — it now has at least 10,000 confirmed cases and more than 630 deaths — saw the Federal Government expand its travel restrictions.

The ban on Italy, which has the largest outbreak outside China, started at 6:00pm AEDT Wednesday.

Australian citizens and permanent residents arriving from Italy, China and South Korea are able to enter Australia, but need to isolate themselves for a fortnight.

With the country in lockdown, Italy has been added to the nations where Australians are advised not to travel to. ( AP: Claudio Furlan )

The decision to put Italy on the list is a change of heart from last week, when Australia added extra screening for arriving passengers from Italy, but stopped short of a ban.

While a relatively small number of countries has been officially classified as 'no-go' zones due to coronavirus, Australians need to be prudent when planning trips for business or pleasure, according to Smart Traveller.

This includes journeys when Australians pass through cities where they are merely changing planes, with Smart Traveller recommending last-minute checks of all points of disembarkation.

Here's an overview of how some popular destinations are affected, including countries with no travel restrictions, but with rising numbers of COVID-19 cases.

Hong Kong

Five more cases on Tuesday brought the city's coronavirus total to 120, while a woman who was thought to have recovered tested positive again.

Schools remain shut in the former British colony, which is on the doorstep of mainland China, where more than 80,000 people have been infected.

Smart Traveller recommends exercising a high degree of caution when flying into Hong Kong, pointing out that even transit passengers "will be subject to increased health screening".

Hong Kong saw five new cases on Tuesday to bring its coronavirus total to 120. ( AP: Kin Cheung )

It added that even having Hong Kong as a stopover on your travel itinerary could prevent flying elsewhere.

Singapore

Qantas has announced that it is re-routing flights to London via Perth to avoid its regular stopover in Singapore.

The island nation has 160 people affected by COVID-19, but has been given the green light by the Australian Government, with only normal safety precautions recommended.

"Expect additional health screening at borders," Smart Traveller said.

"Short-term travellers who do not comply with a request to be tested may be denied entry to Singapore."

Japan

Japan had 59 new cases of the infection on Monday, the biggest one-day rise since the start of the outbreak, reported national broadcaster NHK.

The nation has had 581 infections, but that figure goes up to 1,277 when including the 696 people from the Yokohama-docked Diamond Princess cruise ship last month.

A total of 19 people have died.

The Australian Government is recommending a high degree of caution when travelling to Japan, adding "from 9 March, you'll be required to spend 14 days in quarantine in a designated facility if you arrive in Japan from mainland China, Hong Kong, Macau or South Korea".

United Kingdom

The UK has retained its green-light status as a travel destination for Australians, despite British health minister Nadine Dorries revealing on Monday that she had tested positive for coronavirus.

The conservative politician is the first British member of parliament to contract the virus.

A total of 382 people have been diagnosed with the virus in the UK, and six have died.

Smart Traveller says that Australia has a reciprocal healthcare agreement with the UK and "some treatments are free if you're in the UK for a short visit".

British MP Nadine Dorries is reportedly in isolation after revealing the she has COVID-19. ( Reuters )

France

With 1,784 cases and 33 deaths, France is number five on the global list for COVID-19 cases.

But it is a rung below 'no-go' zones like China, Italy, Iran and South Korea in terms of warning.

Australians should exercise "a high degree of caution" on French soil.

"France has enacted its public health response plan limiting travel to certain areas and cancelling events," Smart Traveller said.

Spain

With 35 fatalities, Spain has two more COVID-19 deaths than France and is only fractionally behind France in terms of overall numbers with 1,695 cases.

On Monday, the Spanish Government stepped up its response to "avoid the Italian scenario" by banning indoor gatherings of more than 1,000 people in certain regions.

Even so, the Australian Government says that travellers should exercise normal safety precautions in Spain.

"Monitor the media and follow the advice of local authorities [in Spain], including compliance with any additional screening measures," Smart Traveller said.

United States

With a spike in confirmed cases over the past week, the US now has more people infected with COVID-19 than Japan and Hong Kong combined to sit in eighth place on the global list.

After a spike in US coronavirus cases, Mr Trump announced a stimulus plan on Tuesday to help sinking markets. ( Reuters: Carlos Barria )

However, Smart Traveller gives the green light for Australians to visit, but advises them to check for updates.

"The US … may deny boarding of any US-bound traveller showing signs of illness. Expect enhanced screening procedures," it said.

India

The world's largest democracy gets an amber rating from the Australian Government, which recommends exercising "a high degree of caution".

Despite its 1.33 billion population, India has reported only 56 cases.

There are no official deaths, although local media said that two Indians died over the weekend "following symptoms of coronavirus".

"Expect additional health screening on arrival, including disclosing your travel history," Smart Traveller said.

Thailand

The Land of Smiles sits just behind India on the global list with 53 cases, and a single death.

Tourist arrivals to Thailand dropped 44 per cent in February, The Bangkok Post newspaper reported.

Tourist arrivals in Thailand dropped by 44 per cent in February. ( AP: Sakchai Lalit )

A high degree of caution is recommended when visiting Thailand, whose government has designated COVID-19 as "a dangerous communicable disease".

Smart Traveller added: "This allows officials to order people suspected of having coronavirus into a hospital for treatment or to mandate quarantine."

Greece

Starting on Tuesday, schools in Greece have been shut down for two weeks after five more cases took the national total to 89, the 12th-highest in Europe.

Although the Australian Government recommends normal safety precautions, it said: "Authorities have suspended mass gatherings at educational institutions, cinemas, sporting venues and other public amenities. These measures may be implemented at short notice."

Indonesia

With 267 million people, Indonesia is South-East Asia's most populous nation, and boasts the popular holiday destination of Bali.

While only 27 cases have been reported in Indonesia, COVID-19 travel warnings greet travellers in Bali. ( AP: Firdia Lisnawati )

Only 27 coronavirus cases have been reported, with no official deaths, although eight more people were infected on Tuesday.

Like some of its ASEAN neighbours, Indonesia is listed by Australia as a destination where a high degree of caution is recommended.

Vietnam

Vietnam has temporarily suspended entry for citizens from Denmark, Finland, France, Germany, Norway, Spain, Sweden and the United Kingdom due to coronavirus outbreak.

The South-East Asian nation has 31 COVID-19 cases, and has yet to report a fatality.

Smart Traveller is recommending normal safety precautions for Vietnam, but said: "Vietnam has introduced new entry restrictions in response to COVID-19".

"You'll be required to complete a mandatory health declaration on arrival to the country."

Philippines

A 44-year-old Chinese man is the only confirmed coronavirus-related death in the Philippines, which says that 33 people are currently infected.

The Philippines gets an amber alert from Smart Traveller, which recommends a high level of caution.

"The Philippines has an ongoing travel ban on China, Hong Kong and Macau, as well as North Gyeongsang (South Korea)," Smart Traveller said.

Qatar

Like Dubai, Qatar is where many Europe-bound flights from Australia pass through.

Qatar has 24 people infected, with six new cases reported this week.

The host nation of the 2022 FIFA World Cup, Qatar has been given a green light for travel, with normal safety precautions recommended.

Earlier this week, the Gulf nation announced the closure of schools and universities from March 10 "until further notice".

New Zealand

Our Tasman neighbour has just five coronavirus cases.

New Zealand health officials said on Tuesday that they were focusing on slowing the spread of the virus by reducing mass gatherings and closing schools.

Normal travel advisories are in place for New Zealand.

"All foreign nationals who travel from or transit through mainland China after 2 February 2020 (NZ time) will be refused entry," Smart Traveller said.