The World Health Organization voiced concern Monday about the spread of the new coronavirus outside China as the global death toll topped 3,000.
More people have died in China, Iran and the United States from the virus, which has now infected nearly 90,000 people with cases in over 60 countries.
The epidemic threatens to cause a global economic slowdown, while airlines cancelled or reduced flights and stock markets swung wildly on Monday.
With fears of a pandemic on the rise after the virus first emerged in China late last year, the WHO urged all countries to stock up on critical care ventilators to treat patients with severe symptoms.
The UN's health agency also announced on Monday that in the last 24 hours there had been almost nine times more COVID-19 cases reported outside China than inside.
Its chief Tedros Adhanom Ghebreyesus said a "window of opportunity" remained to contain the outbreak, noting that "more than 130 countries have not detected any cases yet".
In the countries with cases, the situations in South Korea, Iran, Italy and Japan are currently "our greatest concern", he said.
In Brussels, the European Centre for Disease Prevention and Control (ECDC) increased its risk assessment for Europeans to "moderate to high". Hours later, Italy announced its deaths from the virus had jumped 18 to 52.
The virus has raised fears for the world economy, with the OECD lowering its global growth forecast by half a point to 2.4 percent, the worst performance since the 2008 crisis.
In China, the economy has ground to a halt with large swathes of the country under quarantine or subject to strict travel restrictions. Takings at Macau casinos fell a record 88 percent in February.
Other countries have started to enact their own containment measures, banning arrivals from virus-hit nations, locking in towns, urging citizens to stay home and suspending major events such as football matches and trade fairs.
The Louvre -- the world's most visited museum -- closed on Sunday and Monday after staff refused to work because of fears about the virus, which has now claimed three lives in France.
And in Geneva, the UN headquarters said it was closing its doors to visitors and curbing some activities linked to the UN Human Rights Council, the world body's top rights grouping.
In Italy, tourist hotpots including the Duomo in Milan opened their doors to visitors, but access was limited to avoid overcrowding in a bid to contain the virus.
Italy is Europe's worst-affected country with around 1,700 infections and 52 dead, 18 of them since Sunday.
EU Health Commissioner Stella Kyriakides said there were more than 2,100 confirmed cases across 18 member states.
Elsewhere in Europe, Sweden barred flights from Iran -- where cases have rapidly ballooned -- while France Germany and the UK said they would send medical and financial aid to the Middle Eastern nation struggling to contain the outbreak.
Iran reported 12 more deaths on Monday, raising the country's toll to 66, the second biggest after China.
South Korea Sect
China reported 42 more deaths on Monday -- all in central Hubei province. The pathogen is believed to have originated in a market that sold wild animals in Hubei's capital Wuhan.
The death toll in China alone rose to 2,912, but it is also surging abroad.
The WHO says the virus appears to particularly hit those over the age of 60 and people already weakened by other illness. It has a mortality rate of between two and five percent.
Infections are now rising faster abroad than in China, as the country's drastic measures, including quarantining some 56 million people in Hubei since late January, appear to be paying off.
South Korea, the biggest nest of infections outside China, reported nearly 500 new cases on Monday, raising its total past 4,000.
Half of South Korea's cases are linked to a sect whose leader apologised Monday for the spread of the disease.
Seoul's city government have asked prosecutors to press murder charges against him for failing to cooperate in efforts to contain the virus.
A second person died in the northwestern US state of Washington as President Donald Trump, who has downplayed the risk of a major outbreak, faced criticism over his administration's preparedness.
He was due to hold talks with pharmaceutical executives on the response to outbreak.
New York reported its first case in a woman who had visited Iran, and the governor said he expected the virus to spread in the global financial hub.
After an increase on Sunday, China's National Health Commission reported 202 new infections on Monday, the lowest daily rise since late January, bringing the nationwide total over 80,000.
In a sign of the improving situation, authorities in Wuhan closed on Sunday one of 16 makeshift hospitals built or repurposed from public buildings to treat the city's huge number of patients.
By contrast, Iran reported more than 500 new cases, raising its total number of infections to 1,501.
Four more people died in South Korea, taking its toll to 22.
South Korea's cases are expected to rise further as authorities test more than 260,000 people associated with the Shincheonji Church of Jesus, the religious group often condemned as a cult that is linked to more than half the infections.