(CNN) — The US State Department raised its travel advisory for the United Kingdom to Level 4: Do Not Travel on Monday, aligning with an update made by the US Centers for Disease Control and Prevention (CDC) earlier in the day.
"The Centers for Disease Control and Prevention (CDC) has issued a Level 4 Travel Health Notice for the United Kingdom due to COVID-19, indicating a very high level of COVID-19 in the country," the State Department said in its updated advisory.
"There are restrictions in place affecting U.S. citizen entry into the United Kingdom. Your risk of contracting COVID-19 and developing severe symptoms may be lower if you are fully vaccinated with an FDA authorized vaccine. Before planning any international travel, please review the CDC's specific recommendations for fully vaccinated and unvaccinated travelers."
The advisory level for the UK was most recently Level 3: Reconsider Travel due to Covid-19.
The CDC suggests that people avoid travel to destinations that are classified as Level 4, and that if people must travel there, they make sure they are fully vaccinated before they go.