The US State Department warned Americans Monday not to travel to Germany due to the "very high level of COVID-19 in the country."
The advisory came after fresh advice from the US Centers for Disease Control and Prevention (CDC).
"Avoid travel to Germany. If you must travel to Germany, make sure you are fully vaccinated before travel," the CDC warned.
"Because of the current situation in Germany, even fully vaccinated travelers may be at risk for getting and spreading COVID-19 variants," it added.
Denmark, Belgium, Croatia, Hungary, Austria and the Netherlands have also been issued with the CDC's highest Level 4 warning.
Germany, the EU's most populous nation, is currently grappling with its fourth, and most severe, wave of the pandemic.
On Monday, 30,643 new cases were reported andintensive care units are filling up with COVID-19 patients at a rate German hospitals have never seen before, not even in 2020.
The latest surge has been blamed on a sluggish vaccine uptake. Only 68% of the country's population is fully vaccinated.
Health Minister Jens Spahn made a bleak remark on the course of the pandemic on Monday, as he urged people not to be too picky about the vaccines.
"Probably, by the end of this winter, as is sometimes cynically said, pretty much everyone in Germany will be vaccinated, recovered or dead," he told reporters.
However, Hendrik Streeck, one of the country's top virologists, told DW in an interview that he disagreed with the comment.
"While I agree that the situation is serious right now ... I don't agree with the sentence that everyone after this fall or winter 'will be either vaccinated, recovered or dead,' Streeck, a professor and director of the Institute of Virology at the University of Bonn, said.
"That would mean that everyone will come into contact with the virus this winter," he said, adding that was not how it works.