The United States has declared a public health emergency and announced the dramatic step of barring entry into the country of foreign nationals who have recently visited China.
The U.S. administration on January 31 also said that U.S. citizens who have traveled within the past two weeks to China's Hubei Province will be subject to a mandatory quarantine of 14 days.
Americans returning from other parts of China will be subject to screening at airports and will be required to take 14 days of "monitored self-quarantine" screening measures at home.
The new restrictions take effect at 5 p.m. Eastern time on February 2. Health and Human Services Secretary Alex Azar announced.
"It is likely that we will continue to see more cases in the United States in the coming days and weeks, including some limited person-to-person transmissions," Azar said.
"The American public can be assured the full weight of the U.S. government is working to safeguard the health and safety of the American people."
China slammed the U.S. decision to bar foreign travelers who had visited the country, saying it contradicted the World Health Organization’s (WHO) appeal to avoid travel bans, and "unfriendly comments" that Beijing was failing to cooperate.
Hubei Province and its capital, Wuhan, are considered to be the epicenter of the coronavirus epidemic that has killed at least 259 people and infected nearly 11,800 in China.
At least 25 countries throughout the globe have reported infections on their territory, mainly from people returning from China or having contact with such people. No deaths have been reported outside of China.
The World Health Organization (WHO) has declared the outbreak a global emergency.
The public health emergency declaration in the United States allows the government to tap additional resources to send to states, including, if necessary, drugs or equipment from national supplies.
The White House said an average of more than 14,000 people traveled by air to the United States from China each day last year on direct or indirect flights.
Even with the new measures, U.S. officials stressed that the overall risk to Americans was low.
"I want to emphasize that this is a serious health situation in China, but I want to emphasize that the risk to the American public is currently low," CDC Director Robert Redfield told reporters.
"Our goal is to do all we can do to keep it that way."
On January 30, the State Department warned Americans not to travel to China because of the outbreak.
Japan and Germany also advised against nonessential travel to China. Britain did as well, except for Hong Kong and Macao. Singapore barred Chinese from traveling to the city-state, becoming the first Southeast Asian nation to do so.
The flu-like coronavirus is believed to have originated in a seafood and animal market in Wuhan.
The virus has infected more people globally than were sickened during the 2002-03 outbreak of severe acute respiratory syndrome (or SARS), which is related to the new virus. Both are from the coronavirus family, which also includes those that can cause the common cold.