The head of the World Health Organization on Monday singled out the epidemics in Iran, Italy, Japan and South Korea as the "greatest concern," citing continued increases of new coronavirus cases in the four countries.

"We are in uncharted territory," WHO Director General Tedros Ghebreyesus told a press briefing, while stressing that the containment of the virus "is feasible and must remain the top priority for all countries."

According to WHO data, nearly 88,000 people in 62 countries have been infected with the virus, called COVID-19, leaving more than 2,800 dead around the world.

In addition to the bulk of cases in China, the number of confirmed cases has continued to rise in many countries including the four listed by Tedros.

WHO data show some 4,400 cases reported in South Korea and more than 970 confirmed infections in Japan, while Italy and Iran have seen around 1,700 and 1,500 cases, respectively.

"With early aggressive measures, countries can stop transmission and save lives," the WHO chief added.