The European Centre for Disease Prevention and Control (ECDC) marked Lithuania grey on its Covid-19 map updated every week.
According to the ECDC, the country failed to supply updated information about the pandemic.
Travellers from grey area countries within the EU might be subject to stricter requirements.
Justina Petravičienė, spokeswoman for Lithuania's National Public Health Centre, told BNS on Thursday that the centre was looking into why Lithuania was deemed as having failed to provide data.
“The experts said they had provided data as usual. My colleagues are now in contact with the ECDC to find out the reason why the data is not seen,” Petravičienė said.
Meanwhile, Lithuania is around the middle in the ECDC's statistics table where July 5-18 epidemiological data from 29 European countries are compared. The country's 14-day infection rate stood at 71 per 100,000 at the time.
This rate now stands at 91.4, according to the latest figures from Lithuania's statistics service.