He made the remark in response to a question about some companies stating that tourists who have returned from Chiang Mai and Chiang Rai must undergo self-isolation for 14 days.
"These companies made announcements in response to the discovery of new coronavirus cases, but we have not concluded on whether tourists must undergo 14 days quarantine or not," he said.
"However, people who are travelling in these provinces must take care of themselves, such as by wearing a face mask and washing hands regularly," he said.
As of Saturday, the number of confirmed cases in Thailand had risen to 4,192 (1,204 in state quarantine), 217 are in hospital, 3,915 have recovered and been discharged, while 60 have died.