President Trump’s administration is considering banning travel to China due to the outbreak of the coronavirus, Secretary of State Mike Pompeo said.

“Well, look, the State Department constantly evaluates risk to travelers,” Pompeo told reporters on Wednesday during a flight to London. “That includes travel advisories that could encompass a wide range of things, including banning travel. All of those things will constantly be under consideration.”

Chinese government officials are struggling to contain the outbreak, which reportedly has killed 132 people in China and infected thousands of others. Pompeo refused to “talk about internal deliberations,” but the coronavirus outbreak has spurred calls for travel bans from leaders in the Indo-Pacific and the United States.

“It appears that this coronavirus has a long incubation period, and asymptomatic persons may be able to transmit the virus,” Sen. Tom Cotton, an Arkansas Republican who has worked closely with Pompeo for years, wrote in a Tuesday letter to the administration. “Given these dangerous circumstances, a targeted travel ban is warranted to protect Americans until we know more about the virus and the outbreak is under control.”

[Related: 'All options are on the table': Trump administration considers more travel restrictions as coronavirus spreads]

While the infections are spreading rapidly, the dangers of coronavirus remain unclear, according to health experts. “It appears that the novel coronavirus is better at spreading between humans than the SARS virus, and the outbreak has the potential to be bigger in terms of case counts,” Amesh Adalja, an infectious disease expert at the Johns Hopkins Center for Health Security, said in an interview. “What remains to be seen is the severity level of the outbreak. What is the ratio of mild-to-severe cases?”

The virus originated in Wuhan, the capital of China’s Hubei province, but the crisis is worsening despite mass quarantines that Chinese Communist Party authorities hoped would contain the outbreak.

"The continued increase in cases and the evidence of human-to-human transmission outside China are of course both deeply concerning," Tedros Adhanom Ghebreyesus, World Health Organization director-general, said on Wednesday of his decision to hold a meeting. "Although the numbers outside China are still relatively small, they hold the potential for a much larger outbreak."

Pompeo pledged that the State Department “will evaluate on a continuous basis, literally hour by hour” whether a travel ban is necessary while coordinating with the WHO and Chinese authorities on how to stop the outbreak.

“We want to make sure we get it right,” he said. “At the same time, we don’t want to overreact, either. We don’t want to react in a way that actually has the potential to make things worse and not better.”