The Centers for Disease Control and Prevention has issued a new warning to Americans about traveling to Sweden, Morocco, and Guatemala, adding the three countries to its highest travel risk as COVID cases increased in recent days.

The three nations were previously listed with a Level 2 “moderate” risk warning for travelers, moving up to the Level 3 “high” risk on Tuesday.

A Level 3 destination has had more than 100 COVID cases per 100,000 residents in the past 28 days, the CDC said.

Now, Level 3 is the agency’s highest travel warning, as it has reserved its Level 4 “highest” risk category for special circumstances such as an extreme level of COVID cases, the emergence of a new variant, or a healthcare infrastructure collapse.

Currently, there are no locations in the Level 4 category out of the about 235 places that are being monitored by the CDC.

Sweden now joins much of Europe that is listed in the Level 3 category, along with parts of the Caribbean, Mexico, Canada, Brazil, Malaysia, and Thailand.

Currently, there are about 115 nations listed in the CDC’s Level 3 “high” risk category.

The CDC recommends that American travelers be up to date with their COVID shots prior to traveling to a Level 3 nation but warns that “Even if you are up to date with your COVID-19 vaccines, you may still be at risk for getting and spreading COVID-19.”

Also seeing changes on Tuesday were three locations that were moved into the Level 2 “moderate” risk category for travel – Jordan, Lebanon, and North Macedonia.

A Level 2 destination has between 50 to 100 COVID cases per 100,000 residents in the past 28 days.

Both Jordan and Lebanon saw their COVID situation worsen, moving up from Level 1 “low” risk, while North Macedonia had an improvement in its COVID cases, dropping from the Level 3 “high” risk category.

Currently, there are about 20 nations listed in the Level 2 “moderate” risk category by the CDC, including Colombia, Iraq, Saudi Arabia, Bolivia, Romania, Poland, and Ethiopia.

Updated on the CDC’s Level 1 “low” risk category were two destinations – Saba and Saint Pierre and Miquelon.

A Level 1 destination has between 49 and fewer COVID cases per 100,000 residents reported over the past 28 days.

Both nations had improvements in their COVID cases, with Saba dropping from Level 2 “moderate” risk and Saint Pierre and Miquelon moving down from Level 3 “high” risk.

Also listed in the Level 1 “moderate” risk category are El Salvador, Fiji, Moldova, Indonesia, the Philippines, Cuba, and India.

Finally, the CDC downgraded four locations to its “unknown” category, which includes places where reliable information about their COVID situation is unknown. These destinations may have ongoing warfare or unrest, and it is difficult to determine the risk of traveling there.

Additions to the “unknown” category include Haiti, Hungary, Iran, and Mozambique. Haiti, Iran, and Mozambique were previously listed at Level 1 “low” risk, and Hungary sat in the CDC’s Level 3 “high” risk category.

The CDC advises against traveling to an “unknown” risk nation due to the high risks of contracting COVID-19. Other destinations listed in the “unknown” risk category include Macau, the Maldives, Belarus, Libya, French Polynesia, and Venezuela.