The U.S. State Department has added about 100 countries this week to its "Level Four: Do Not Travel" advisory list, putting Croatia, the United Kingdom, Canada, France, Mexico, Germany and others on the list, citing a "very high level of COVID-19," Reuters reported.

On Monday, the State Department said it would increase the number of countries receiving its highest advisory rating to about 80% of countries worldwide.

Before Tuesday, the State Department listed 34 out of about 200 countries as “Do Not Travel.” The State Department now lists about 131 countries at Level Four, says Reuters.

The State Department said Monday the move “reflects an adjustment in the State Department’s Travel Advisory system to rely more on (Centers for Disease Control and Prevention’s) existing epidemiological assessments.”

Other countries in the “Do Not Travel” list include Finland, Egypt, Belgium, Turkey, Italy, Sweden, Switzerland and Spain.

Some countries like China and Japan remain at “Level 3: Reconsider Travel.”

Most Americans already had been prevented from traveling to much of Europe because of COVID-19 restrictions. Washington has barred nearly all non-U.S. citizens who have recently been in most of Europe, China, Brazil, Iran and South Africa, Reuters says.

On Tuesday, the United States extended by another 30 days restrictions barring non-essential travel at its Canadian and Mexican borders.