The fight against the spread of coronavirus has reached new battlegrounds with more new cases of the disease reported outside China than inside for the first time.

On Tuesday, 411 new cases of the COVID-19 disease were reported in China, while 427 were reported outside the country, the World Health Organisation (WHO) said.

"Yesterday, the number of new cases reported outside China exceeded the number of new cases in China for the first time," WHO chief Tedros Adhanom Ghebreyesus told diplomats in Geneva.

Countries across the world are now scrambling to prevent the spread of the virus, which was first detected at a seafood market in Wuhan in December.

In the last three months, more than 80,000 people have been infected across 40 countries, while more than 270 have died.

The latest countries to be hit included Algeria, Austria, Croatia, Greece and Switzerland on Wednesday.

South Korea announced more than 1000 infections – by far the largest outside China – and 12 deaths, while Italy, the hardest hit country in Europe, had more than 370 cases and 12 deaths.

Iran announced a total of 19 deaths and 139 infections, including the country's deputy health minister.

In the US, President Trump will give a press conference about the virus on Wednesday after mixed messages had been sent from the US administration.

The Centers for Disease Control and Prevention warned the American public to prepare for an outbreak of the disease.

But before he flew home from India on Tuesday, Trump said the coronavirus situation is "very well under control in our country."

The administration has asked Congress for an additional $2.5 billion to speed development of a vaccine, support preparedness and response activities, and to gather needed equipment and supplies.

IS IT A PANDEMIC YET?

Around the world cleaning crews scrubbed down everything from money to buses and military bases and hotels were on high alert for the disease.

Worries about the economic impact are growing with factories idle and tourism crippled.

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The dramatic surge of infections in Italy, Iran and South Korea has prompted calls for the virus to be declared a pandemic.

The WHO defines a pandemic as a situation where "the whole world's population" is likely to be exposed to an infection and potentially "fall sick".

The declaration would prompt countries to step up their preparedness plans, but the WHO said it could also cause unnecessary panic.

"We should not be too eager to declare a pandemic," Dr Tedros said on Wednesday, stressing that such a declaration could "signal that we can no longer contain the virus, which is not true".

"We are in a fight that can be won if we do the right things."

But Dr Tedros insisted the WHO would not hesitate to declare a pandemic if it was "an accurate description of the situation".

"I am not downplaying the seriousness of the situation, or the potential for this to become a pandemic, because it has that potential," he said.

"All countries, whether they have cases or not, must prepare for a potential."

VIRUS COULD STICK AROUND FOR MONTHS

The coronavirus epidemic is believed to have peaked in China between January 23 and February 2.

But Bruce Aylward, the leader of a joint WHO-China mission of experts, said it could still hang around "for months".

On Tuesday, he told warned that countries needed to do more to get ready.

"Think the virus is going to show up tomorrow. If you don't think that way, you're not going to be ready," he said.

"This a rapidly escalating epidemic in different places that we have got to tackle super-fast to prevent a pandemic."

US President Donald Trump said he would hold a news conference at the White House on Wednesday to discuss the coronavirus threat.

It comes after the Centers for Disease Control and Prevention (CDC) warned the American public to prepare for an outbreak.

"It's not so much a question of if this will happen anymore, but rather more a question of exactly when this will happen, and how many people in this country will have severe illness," senior official Nancy Messonnier said.

She said schools could help contain the spread by closing down or using "internet-based teleschooling" while businesses could "replace in-person meetings with video and telephone conferences".

On a larger scale, cities may need to cancel mass gatherings, she added.