Residents in the United States are being advised not to travel to Canada as COVID-19 hospitalizations hit critical levels.

The U.S. Centers for Disease Control and Prevention issued a Level 4 notice to “avoid travel” to Canada due to the emerging COVID-19 situation.

Travellers are urged to be fully vaccinated if they do plan on making the trip up north.

“Because of the current situation in Canada, even fully vaccinated travelers may be at risk for getting and spreading COVID-19 variants,” reads the advisory on the CDC’s website. “Travelers should follow recommendations or requirements in Canada, including wearing a mask and staying 6 feet apart from others.”

The U.S. Department of State also upgraded its advice to a Level 4 which states residents should “not travel to Canada due to COVID-19.”

Back in December, the Canadian government issued its own advisory, warning residents against all non-essential international travel due to Omicron.

Canada currently has more than 400,000 active cases of COVID-19.