More new coronavirus cases have for the first time been reported outside China than inside, World Health Organisation chief Tedros Adhanom Ghebreyesus has said.
In China, the number of new cases reported on Tuesday was 411, whereas in the rest of the world the number was 427.
The total number of cases globally has now reached 80,980.
The WHO chief said the sudden rise in coronavirus cases in Italy, Iran and South Korea was "deeply concerning" but the virus could still be contained and did not amount to a pandemic.
Several European countries have announced their first coronavirus cases, all apparently linked to the growing outbreak in Italy.
Austria, Croatia, Greece and Switzerland said the cases involved people who had been to Italy, as did Algeria in Africa.
The first positive virus test has been recorded in Latin America - a Brazilian resident just returned from Italy.
Italy has in recent days become Europe's worst-affected country.
Authorities have confirmed more than 300 cases and 12 deaths there, the most recent a 70-year-old resident of Lombardy who died after being taken to intensive care in Parma. The country has also seen four children infected.
Its neighbours, however, have decided closing borders would be "disproportionate".
Health ministers from France, Germany, Italy and the EU Commission committed to keeping frontiers open at a meeting on Tuesday as new cases of the virus emerged throughout Europe and in central and southern Italy.
"We're talking about a virus that doesn't respect borders," said Italian Health Minister Roberto Speranza.
His German counterpart, Jens Spahn, said the neighbours were taking the situation "very, very seriously" but acknowledged "it could get worse before it gets better".
In the UK, schoolchildren returning from holidays in northern Italy have been sent home, with the government issuing new guidance to travellers. But Health Secretary Matt Hancock said there were no plans to stop flights from Italy, which attracts about three million British visitors each year.
"If you look at Italy, they stopped all flights from China and they're now the worst-affected country in Europe," he said.
Read more about the Covid-19 coronavirus:
- Covid-19: What it is and how to protect yourself
- Analysis: How close to a pandemic?
- How it affects the global economy
- Opinion: As coronavirus spreads, so does racism and xenophobia
- Coronavirus patient 'never really felt unwell'
- More Covid-19 news
On Tuesday the US Centres for Disease Control said it would be a matter of if, not when coronavirus becomes a pandemic.
However the WHO said using the word pandemic would signal that the virus cannot be contained which isn't true.
"We are in a fight that can be won if we do the right things," Tedros Adhanom Ghebreyesus said.
"For the moment, we are not witnessing sustained and intensive community transmission of this virus, and we are not witnessing large-scale severe disease or death."
The WHO argued that China has had fewer than 80,000 cases out of a population of 1.4 billion people and in the rest of the world, there have so far been 2790 cases out of a population of 6.3 billion.
Ireland v Italy Six Nations games off
Ireland's men's and women's Six Nations games against Italy in Dublin on 7 and 8 March have been postponed because of coronavirus.
Irish Health Minister Simon Harris said on Tuesday the men's game should be postponed and met with the Irish Rugby Football Union (IRFU) on Wednesday.
Eleven towns in northern Italy are in lockdown after an outbreak.
An IRFU statement said it hoped to give an update on the rescheduling of matches "in the coming days".