Milan: The Italian Prime Minister has defended his government's handling of an expanding coronavirus cluster as fresh cases are confirmed in three new European countries and health ministers downplay potential border closures as "disproportionate and ineffective".

The death toll on Tuesday climbed to 10 and the number of confirmed cases rose by more than 100 to hit 322, according to an update from the country's civil protection department.

The vast majority of cases are in the Lombardy region, in the country's north.

Walter Ricciardi of the World Health Organisation stressed that for every 100 cases, about 80 people get better alone, 15 have serious but manageable problems, five are very serious and about three die.