The U.S. Centers for Disease Control and Prevention on Monday raised its travel advisories for Singapore and Hong Kong by one level each.

Singapore was raised from Level 2 to Level 3, indicating a “high” level of Covid-19 in the country. The CDC said unvaccinated travelers should avoid nonessential travel to the Southeast Asian country.

“Because of the current situation in Singapore, all travelers may be at risk for getting and spreading Covid-19 variants,” the agency said.

Singapore’s Covid infections have surged to new highs in the past week. Tighter restrictions kicked in on Monday in a bid to slow virus transmission.

The U.S. State Department also revised its advisory for Singapore to Level 3, recommending citizens “reconsider travel.” The city-state was previously classified as Level 2, which suggests travelers should “exercise increased caution,” due to Covid-19.

Travelers should also reconsider travel to Hong Kong, according to a department advisory last updated June 16. In that notice, the State Department cited “arbitrary enforcement of local laws” as well as Covid-related travel restrictions.

This week, the CDC raised its travel health advisory for Hong Kong from Level 1 to Level 2, indicating a shift from “low” to “moderate” levels of Covid.

Unvaccinated travelers who are at increased risk of severe illness from the coronavirus should avoid nonessential travel to the Chinese city, the updated recommendation said.

The agency says travelers going to Level 2 or 3 destinations should make sure they are fully vaccinated before visiting.

Hong Kong’s daily reported Covid cases have been in the single digits for the past week. All the infections were imported cases.

As of Sunday, the U.S. reported an average of 359 daily new Covid cases per million people in the past seven days, compared with 244 per million in Singapore and 0.62 per million in Hong Kong, according to Our World in Data.

The CDC has four levels in its Covid-19 travel health recommendations:

• Level 1: Low
• Level 2: Moderate
• Level 3: High
• Level 4: Very high

All travelers are advised to avoid going to Level 4 destinations. The agency also notes it relies on data from the World Health Organization and other official sources to make its determinations. The CDC said, however, that there is insufficient data for regions listed as “level unknown” and travelers should follow Level 4 recommendations.

The State Department also has four levels in its travel advisory system, but includes a wider range of factors in its classification. While the CDC focuses on health, the State Department also evaluates risk factors like crime, terrorism, unrest, natural disasters and kidnapping.

• Level 1: Exercise normal precautions
• Level 2: Exercise increased caution
• Level 3: Reconsider travel
• Level 4: Do not travel

The department’s advisories now include information on Covid risks for each destination, often citing CDC travel health recommendations.