Germany on Friday declared the whole of France a "high risk" area for coronavirus infections, a move that means travellers need to show a negative Covid-19 test and quarantine upon arrival.
France, including all French overseas departments, is now considered "at particularly high risk of infection due to a particularly high number of cases", Germany's Robert Koch Institute for infectious diseases said.
Anyone travelling from France will have to be able to produce a negative test that is less than 48 hours old upon entry, before beginning a 10-day quarantine period in Germany.
Slovakia and the Czech Republic were meanwhile downgraded from the highest alert red list of "virus variants regions" to "high risk" areas.
Austria's hard-hit Tyrol region, which borders Germany, is also no longer considered a virus variant region and is now classified as a lower-level risk area, RKI added.
The travel updates come as Germany struggles to halt a sharp in new infections amid a slow vaccination drive and the spread of new, more contagious virus strains first detected in Britain, South Africa and Brazil.
Coronavirus incidence rates, which measure the number of infections in every 100,000 people over the previous seven days, have crossed the threshold of 200 in numerous French departments.
In Ile-de-France, the region which encompasses the capital of Paris, it has passed 600.
German Chancellor Angela Merkel had warned on Thursday that France faced tougher entry requirements.
"While we see such a high incidence it is simply a necessity... a practically automatic process," Merkel told reporters.
"It is not related here to a political decision but when we see the evolution of the incidence rate -- as is the case here -- exceed the threshold of 200 for a long time, that requires a classification as a zone of high risk," she added.
Up until now, only France's border area of Moselle had been classified by Germany as an area of particularly high risk, because of the rapid spread of the South African virus variant there.
Merkel hinted however that the France-wide high-risk classification would not necessarily lead to the same kind of strict border controls seen along the Czech and Austrian frontiers.
"There is a whole specific test procedure... that is in discussion with France," Merkel said.