Effective immediately from 3 March 2020, anyone travelling from Mainland China, Hong Kong, Macau, Korea and Italy in the past 21 days will not be allowed into Nauru.
According to the Ministry of Health and Medical Services, the travel restriction and measures will remain in place until a new issuance.
The World Health Organisation reports more than 93,000 people have been infected in more than 80 countries.
Four new Member States (Argentina, Chile, Poland and Ukraine) have reported cases of COVID-19 in the past 24 hours.
In China, there have been 38 new deaths bringing the total to 2,984 and there are 80,422 cases in all.
South Korea, the nation worst hit by the outbreak outside China, reported 516 new cases on Wednesday, bringing its total to 5,328.
There have been more infections recorded in Australia, Japan and New Zealand.
The Ministry of Health said Nauru must take very strong appropriate measures to prevent the importation of the coronavirus at all costs as well as support and assist the rest of the Pacific Island Countries and Territories to mitigate the outbreak.
Photo file Caption: Nauru International Airport