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.

Washington had also reportedly been considering banning entry from Japan as well, amid a spate of new coronavirus cases, with U.S. television network CNN quoting a high-ranking U.S. official as saying that Tokyo may become subject to the entry ban. However, Saturday's announcement made no mention of Japan.

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.