(Reuters) – The United States is considering new steps to counter a coronavirus outbreak that has killed over 100 people in China and nothing is off the table in terms of possible travel restrictions for China, the U.S. health secretary said on Tuesday.

The United States, which so far has five confirmed cases of the new coronavirus, has urged Americans to reconsider or postpone travel plans to China because of the outbreak. It also warned specifically against travel to the Hubei province, the epicenter of the outbreak in China with thousands of cases. [nL4N29V0FY]

Secretary of Health and Human Services Alex Azar said during a news conference that he had offered to send a team of U.S. infectious disease experts to China to assist with its public health efforts and that more cooperation and transparency would help make the response more effective.

“Beyond that, all options for dealing with infectious disease spread have to be on the table, including travel restrictions,” he said.

The World Health Organization (WHO) said on Tuesday that China has agreed it can send international experts “as soon as possible.” It was not clear when a WHO delegation would head to China and what countries would participate in the mission.

The United States is seeking on-the-ground access to study health data that might confirm if the virus can spread before people have symptoms such as a fever, and to help with China’s disease containment measures, Azar and other U.S. health officials said during the news conference.

Despite its fast spread, Azar said risks of the disease are unclear as the United States is still learning about its severity, incubation period and whether there is a real danger of it being transmitted by people without symptoms.

There was no evidence of person-to-person transmission in the United States, Azar said, adding that it was not necessary for Americans to wear surgical masks in public places.

He did not say what specific travel restrictions are being considered. The United States is expanding screenings of travelers from China and has centers monitoring their health at 20 airports, up from five.

The novel coronavirus has killed 106 people, spread across the world and rattled financial markets. The number of confirmed cases in China surged to 4,515 as of Monday, according to the Chinese government.

(Reporting by Manas Mishra in Bengaluru and Caroline Humer in New York; Editing by Sriraj Kalluvila and Bill Berkrot)