COVID is continuing to rise rapidly across the US and the world due to the highly contagious omicron variant.
Canada and Curaçao join multiple other countries on the list, including the majority of Europe and parts of Africa. The CDC also has travel on cruise ships on its Level 4 warning list.
Canada was moved to the US Centers for Disease Control and Prevention’s highest-risk category for travel.
The world’s second-largest country by total area, Canada has seen a steep rise in cases as the Omicron variant spreads.
Canada was joined by one other destination — the Caribbean island of Curaçao — in moving up to the CDC’s Level 4: Covid-19 Very High category on Monday.
The CDC places a destination at Level 4 when more than 500 cases per 100,000 residents are registered in the past 28 days. The CDC advises travelers to avoid travel to Level 4 countries.
Most international visitors to Canada are required to be vaccinated and to have a negative Covid-19 test result.