(U.S. President Donald Trump holds up a graphic from a study he says names the United States as the country most prepared to handle a pandemic during a news conference on Feb. 27)[Getty/Kyodo]

WASHINGTON - The U.S. government said Saturday it will ban the entry of travelers from Iran amid concerns over the spread of the new coronavirus there, while issuing an alert to U.S. citizens not to travel to some virus-hit areas of South Korea and Italy.

The United States, which has barred the entry of foreign nationals who have been in mainland China within the past 14 days, will extend the ban from Monday to include foreign nationals who have visited Iran within the last 14 days.

Concerns are growing that the United States may also see a major outbreak of the pneumonia-causing virus, with infection cases without a known source of exposure emerging in the country. Health officials announced the same day the first reported death in the United States from COVID-19, the official name of the disease caused by the virus.

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President Donald Trump emphasized in a press conference that the United States is prepared for "any circumstance" and that there is "no reason to panic at all."

CNN reported Friday that the government was considering imposing new restrictions on travelers from Japan and South Korea, citing people familiar with the matter. But no new measures were taken against travelers to and from Japan.

Japan has confirmed more than 900 infection cases, although a large portion of them have been linked to the Diamond Princess, a cruise ship quarantined near Tokyo. South Korea has recently seen a surge in infections, with the number of cases surpassing 3,000.

Concerning the travel advisory, the State Department issued a level 4 travel alert, which means "Do Not Travel," to Daegu in the southeast of South Korea as well as to two northern areas of Italy -- the northern Lombardy region, home to Milan, and Veneto, which includes Venice.

For the whole country, South Korea and Italy are both at level 3, which advises travelers to "Reconsider Travel."