September 27 (UPI) – The U.S. Centers for Disease Control and Prevention on Monday moved Norway to its highest travel warning for U.S. citizens considering visiting the Scandinavian country.

The CDC has elevated Norway to Level 4: Very High COVID-19, the highest level in its four-tier review.

“Avoid traveling to Norway,” he said. “If you have to travel to Norway, make sure you are fully vaccinated before traveling.”

A Level 4 designation indicates that a destination has recorded 500 positive cases per 100,000 population in the past 28 days.

The CDC made the adjustment following Norway’s entry this weekend into the first phase of its plan to open up the country, which included lifting entry restrictions for nationals of European countries. It is also dropping entry requirements such as the need to quarantine for a large number of other nations.

The so-called normal daily life with an increased preparedness plan came as the Norwegian Institute of Public Health said its outbreak is expected to decline over the next few weeks and “stabilize at a low level”.

“We have lived for a long time with strict border measures,” said Monica Maeland, Minister of Justice and Emergency Management, in a statement announcing the relaxation of restrictions. “This has been important in the fight against import infections. When we now move on to normal daily life, the government is proposing a gradual reduction in restrictions on entry into the country. This will be done under close surveillance.”

According to the Norwegian Institute of Public Health, Norway has more than 186,000 infections and 850 deaths from the pandemic.

The health authority also added Bulgaria to level 4.

The European nation is by far the least vaccinated country of the 27 countries, according to the Our World In Data project at the University of Oxford, with less than 16% of its 7 million people fully vaccinated.

On Monday, the CDC also moved six countries to level 3, meaning they have an incidence rate of 100 to 500 cases per 100,000 people in the past 28 days.

These countries are: Bangladesh, Equatorial Guinea, Panama, Saint-Barthélemy, Singapore and Slovakia.

Gabon, Hong Kong and Zimbabwe were moved to level 2 and no country was moved to the lowest level 1.