The United States government issued a travel warning for South Korea on Monday, citing numerous COVID-19 illnesses in the country's northeast Asian neighbor.

As a result of the addition of South Korea to the "extremely high" risk Level 4 category by the Centers for Disease Control and Prevention (CDC), it joins a group of five other nations and territories that include Azerbaijan, Belarus, Comoros, French Polynesia, and Saint Pierre and Miquelon.

"If you must travel to South Korea, make sure you are fully vaccinated and up to date on your COVID-19 immunizations before you depart," the Centers for Disease Control and Prevention (CDC) said on its website. It is possible to contract and distribute COVID-19 even if you are up to date on your COVID-19 vaccinations, according to the CDC.

The number of locations susceptible to Degree 4, the highest level of risk determined by the Centers for Disease Control and Prevention, has increased to over 140 throughout the world.

Travel advisories for South Korea have been upgraded to "Level 4: Do Not Travel" by the United States Department of State.

On Monday, South Korea recorded 54,619 new COVID-19 infections as a result of the rapid spread of the highly transmissible omicron strain throughout the country, according to official figures.