"We have entered a phase that will last weeks and, undoubtedly, months," said President Emmanuel Macron of France, where more than 200 people were infected.

As new cases were dropping in worst-hit China, worrisome clusters were growing sharply in South Korea, Italy and Iran, which each exceed 2000 cases. Italy newly surpassed Iran with the most deaths outside China, with 79 as of Tuesday.

World Health Organisation leader Tedros Adhanom Ghebreyesus said though the virus caused more serious illness and death than the flu, data suggests it's not as easy to catch.

"People are afraid and uncertain. Fear is a natural human response to any threat," Tedros said. "But as we get more data, we are understanding this virus and the disease it causes more and more."

In Daegu, the South Korean city at the centre of that country's outbreak, a shortage of hospital space meant about 2300 patients were being cared for in other facilities while they awaited a hospital bed.

"I feel assured that we can absolutely overcome this situation," said Prime Minister Chung Se-kyun in a meeting about quarantine strategies in Daegu.

China reported 119 new cases on Wednesday, all but five in the outbreak's epicentre of Wuhan. In a sign of the shifting threat, Beijing's health commissioner said two new cases in the Chinese capital were apparently infected abroad, in Iran and Italy.

The state-run Xinhua news agency said Hubei province, where Wuhan is located, was expected to gradually shut down its hastily built temporary hospitals, where thousands of beds were empty.

"We believe this decline is real," WHO outbreak expert Maria Van Kerkhove said of China. The country has reported 80,270 infections and 2981 fatalities. It has about 85 per cent of the world's cases and 95 per cent of deaths from the COVID-19 illness.

Italy's death toll rose sharply on Tuesday, with 45, mostly in the northern region of Lombardy where its outbreak has been concentrated.

Fear over the virus' spread led even the Vatican to insist Pope Francis was not infected. He became ill last week, but the Vatican said Francis only had a cold.

The outbreak was blamed for market instability around the globe. Asian stock markets were mixed on Wednesday after Wall Street continued its zigzag performance, despite an interest rate cut by the Federal Reserve.

Business of all types were experiencing pain as travel and tourism were spurned and worried consumers changed their habits.

"People are afraid to touch anything or take anything from us," said Maedeh Jahangiri, a perfume seller at an upscale mall in the Iranian capital of Tehran. "Everyone is at a loss."

Iran has counted 2336 cases of the virus, reportedly even infecting at least 23 members of parliament.

Sixteen Italian tourists who have been travelling in India for the past two weeks have tested positive for the new coronavirus and are being treated in isolation wards.

These cases have taken the total number of positive cases in India to 28 so far, federal Health Minister Harsh Vardhan says.

Japan's northern island of Hokkaido reported three more cases of coronavirus infections on Wednesday, bringing the total to 82 in the prefecture.

The new cases all involve men, one in his 50s and the other two in their 60s, the prefecture said on its website.

Hokkaido accounts for the highest number of infections among Japan's prefectures.

Spain had dozens of health workers quarantined or being monitored after at least five were infected with the new virus.

Poland announced its first confirmed case of the coronavirus on Wednesday.

In total, 500 people are being currently quarantined in Poland, while 68 people suspected of having contracted the virus are treated in hospitals.

In France, the government requisitioned all current and future stocks of protective masks to ensure they go to health workers and patients.

In the United Kingdom, Prime Minister Boris Johnson warned cases could spread, unveiling a 25-page plan for a worst-case scenario in which retired doctors and nurses are called back to work and police could stop investigating minor crimes to help deal with an outbreak.

In the US, nine people have died, all in and around Seattle, Washington, where there was fear a statewide total of 27 infections could drastically rise. The US overall had more than 120 cases.

On Capitol Hill, lawmakers were expected to finalise an agreement on Wednesday on a $US7.5 billion ($A11.4 billion) emergency bill to fund work on a virus vaccine and other measures.

Australian Associated Press