Russian authorities said Tuesday they will impose a temporary entry ban for all Chinese nationals amid the coronavirus outbreak that has infected more than 73,000 people worldwide since December.

The ban goes into effect on Thursday at midnight Moscow time, according to a decree signed by Russia's Prime Minister Mikhail Mishustin. The measure was taken due to "worsening epidemiological situation" in China, where the virus originated.

So far, Russia has had only three confirmed cases of the COVID-19 disease caused by the virus — two Chinese citizens who have been treated and released and a Russian national who contracted the illness aboard the Diamond Princess cruise ship quarantined in Japan.

Still, Russian authorities have taken vast measures to prevent the spread of the virus, including hospitalizing hundreds of people who returned from China as a precaution.

Russia has also halted most air traffic to China, suspended all trains to China and North Korea and closed its land border with China and Mongolia. Moscow has also temporarily stopped issuing work visas to Chinese citizens and told Chinese students who had been studying in Russia not to return until March 1.

Earlier this month, Mishustin also said that Russia may start deporting the foreigners infected with the virus.

Wuhan hospital director dies

As a mysterious new virus enveloped central China's Wuhan early this year, Liu Zhiming mobilized all the resources of his hospital in the city's Wuchang district to deal with the thousands of sick people arriving daily, threatening to overwhelm the local health-care system.

That dedication appears to have cost him his life, with Wuhan's health bureau announcing Tuesday that he became infected and died despite "all-out" attempts to save him.

Liu is at least the seventh health worker to die of COVID-19 among the more than 1,700 doctors and nurses who have become sick. His death comes as authorities are cautiously cheering a reduction in the number of new daily cases and deaths, along with the results of a study showing most people who contracted the virus experienced only mild symptoms.

A screen capture from China Central Television shows Liu Zhiming, who died after contracting the coronavirus that causes COVID-19. The Wuhan Municipal Health Commission said he had taken part in the battle against the virus from the start of the outbreak. (China Central Television/Reuters)

China's National Health Commission said on Wednesday that there were 1,749 new confirmed cases on Tuesday, bringing the total number of confirmed cases in mainland China to 74,185.

It also said the death toll from the outbreak reached 2,004 as of the end of Tuesday, up by 136 from the previous day.

"Now the prevention and control work is at a critical time," President Xi Jinping told British Prime Minister Boris Johnson in a phone call Tuesday, according to Chinese state broadcaster CCTV.

The UN secretary general told The Associated Press that the virus outbreak "is not out of control but it is a very dangerous situation."

Patients infected with the coronavirus are seen at a temporary hospital converted from Wuhan Sports Center in Wuhan, China, on Monday. (Xiao Yijiu/Xinhua via AP)

António Guterres said in an interview in Lahore, Pakistan, that "the risks are enormous and we need to be prepared worldwide for that."

Outside China, there were 804 cases in 25 countries, WHO Director General Tedros Adhanom Ghebreyesus said at a briefing Tuesday in Geneva.

Tedros went on to say there have been 92 cases of human-to-human spread of the coronavirus in 12 countries outside China but the World Health Organization does not have the data to make comparisons with China.

WATCH: WHO officials talk about how China has responded the COVID-19 outbreak.

The World Health Organization says China's handling of the coronavirus outbreak has been 'progressive' 1:43

He said the WHO had not seen sustained local transmission except in specific cases, such as on the Diamond Princess cruise ship quarantined in Japan. Canadian officials said Tuesday that there are 43 Canadians among the confirmed cases from the ship.

The outbreak has caused massive disruptions and China may postpone its biggest political meeting of the year to avoid having people travel to Beijing while the virus is still spreading. One of the automotive industry's biggest events, China's biannual auto show, also is being postponed, and many sports and entertainment events have been delayed or cancelled.