The 24-year-old has just 18 months remaining on his contract and has been widely reported to have agreed a £12 million move to Old Trafford.
However, speaking to Kicker, Watzke has claimed that a winter move would take place for "no price in the world" before reiterating that the club have "high goals" this season.
Lewandowski has scored 53 goals in 115 appearances for Jurgen Klopp's side since joining the club from Lech Poznan in 2010.
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Dortmund director Michael Zorc reiterated their stance to Bild, stating that Lewandowski "is not for sale at any price this winter. We still have our own ambitions."
Despite seemingly missing out on Lewandowski in January, United have boosted their forward line in the short term by recalling wideman Gyliano van Velzen from his loan spell with Royal Antwerp.
The 18-year-old had initially agreed a deal to stay with the Belgian side for the entirety of the season, but has returned to Old Trafford after impressing since the summer.