The Reds are scheduled to face the Bundesliga side at the Red Bull Arena on February 16 at the start of the knockout stages in the competition.
However, restrictions have been imposed in Germany since Saturday on entry for all arrivals from areas affected by COVID-19 mutations until at least February 17.
Exceptions are in place for German citizens or residents but will not be extended for elite sports.
"The Corona Protection Ordinance passed by the German government last Friday provides for only a few exceptions and no special regulations for professional athletes," read a widely released statement from the German government.
"The Federal Police informed the club RB Leipzig today that the described case does not fall under the exceptions."
Rules were put in place by UEFA allowing last-16 ties to be switched, so Anfield could yet theoretically host the opening contest. The game could also be held at a neutral venue, with the possibility open for the tie to be reduced to a single fixture.
When contacted by Stats Perform News, European football's governing body said it remains in dialogue with both clubs and also the German Football Association, who in turn are in contact with the German government.