Thailand's tourism authority yesterday issued a recommendation for visitors from four high-risk countries to postpone their travel to the kingdom.

Citing a separate announcement in the Royal Gazette designating China (including Hong Kong and Macau), South Korea, Italy and Iran as "Disease Infected Zones of the Coronavirus Disease 2019", it said: "The Tourism Authority of Thailand (TAT) would like to recommend travellers from these territories that if the travellers feel these measures will be inconvenient for travelling in Thailand, they may consider postponing travel to another period and await further advice from Thailand's Ministry of Public Health regarding the health measures involved."

The statement helped clarify confusion this week over Thailand's quarantine measures. There had been conflicting statements from the authorities in recent days about which countries were affected and whether a quarantine was mandatory for travellers.

Thailand's Health Ministry had also said yesterday that those arriving in the country from coronavirus-hit places, including Singapore, do not have to quarantine themselves.

Countries on the Health Ministry's watchlist include China, South Korea, Italy and Iran, as well as other countries such as Switzerland, the Netherlands, the United States and Spain.

The ministry said that while a two-week self-quarantine was not compulsory, it was recommended.

"We haven't yet enforced the law to quarantine everyone except for the Thai workers returning from South Korea," Dr Thanarak Phaliphat, deputy director of the Disease Control Department, told a news briefing.

The announcement came one day after the Royal Gazette published the list of "Disease Infected Zones of the Coronavirus Disease 2019" in order to prevent and control the outbreak effectively.

Dr Thanarak said yesterday that visitors from these six places will be required to report to the Health Ministry.

"What we will proceed with in the next day or two is to require everyone coming from (these places) to report their symptoms daily through the Health Ministry's channels," he added. These communication channels include an app and the ministry's hotline number.

Dr Thanarak did not say how these reporting requirements would be enforced.

Thailand draws about 40 million tourists a year. However, the coronavirus outbreak has severely affected these numbers. The Tourism Authority of Thailand confirmed on Thursday that the country could see a loss of six million visitors this year, reported Agence France-Presse.

There were 48 confirmed virus cases in Thailand as of yesterday, with the latest case being a British man who travelled from London and transited in Hong Kong. There has been one death: A 35-year-old Thai retail worker.

Meanwhile, the local health authorities are bracing themselves for the return of thousands of undocumented Thai workers from South Korea, which has the highest number of coronavirus cases outside China at more than 6,500.