Azar said the president took "decisive action" to minimize the spread of the virus in the USA and that the "prudent, targeted and temporary" actions will reduce pressure on public health officials screening incoming travelers and ensure that resources are focused on the health and safety of Americans.
In Australia, Prime Minister Scott Morrison said the country will deny entry to all foreign nationals travelling from mainland China from Saturday.
More than 100 cases have been reported outside China, in 22 countries. On Thursday, the CDC confirmed the sixth case of coronavirus, also known as 2019-nCoV, and it was the first case of person-to-person transmission in the United States. They were to be screened for fever before being taken to two quarantine centers.
The US, Japan, the UK, Germany and some other affected nations have already advised their citizens not to travel to China.
But almost 10,000 people have been infected with the new coronavirus, most in China, since it emerged in December.
The restrictions don't apply to immediate family of American citizens and permanent residents.
On Saturday, Ministry spokeswoman, Hua Chunying, said although the World Health Organization has only just specifically advised against any travel restrictions, the U.S. has made a decision to act in the opposite way.
Growing numbers of major airlines have suspended or reduced China flights, while corporate names ranging from Toyota to McDonald's and Starbucks have shut down Chinese stores or production lines.
SARS, which is similar to the new coronavirus and also originated in China, killed 774 people worldwide, most in China or Hong Kong.
The number of people infected and China's national death toll are expected to climb further once other regions report their latest statistics.
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A seventh USA case of novel coronavirus was confirmed by the CDC late Friday in Santa Clara County, California.
Redfield added that the self-isolation for US citizens returning from China was the standard for the 2014 Ebola outbreak in West Africa, and "98% of the American public voluntarily accepted the importance of this".
But Dr. Nancy Messonnier, director of the CDC's National Center for Immunization and Respiratory Diseases, told reporters on Friday that experts' understanding of the virus was still evolving. "There are 4 million Chinese-Americans in this country".
At least 24 countries have reported cases since China informed World Health Organization about the new virus in late December.
The epidemic has led to mass evacuations of foreign citizens as world airlines halt flights, and risks exacerbating a slowdown in growth in the world's second-largest economy. The official Xinhua News Agency said people in Hubei who work outside the province also were given an extended holiday.
Meanwhile, iPhone-maker Apple announced Saturday that it was closing all of its 42 stores as well as its corporate offices in mainland China, one of its largest markets, until February 9.
The federal quarantine order is the first since 1963, when a woman returned from a trip to Sweden during a smallpox outbreak and couldn't prove she had been vaccinated.
The CDC says that even if a screening test comes back negative, it does not conclusively mean an individual is at no risk of developing the disease over the 14-day incubation period.
None of the Americans being housed at a Southern California military base has shown signs of illness, but infected people don't show symptoms immediately and may be able to pass on the virus before they appear sick.