Citigroup has barred its New York customers from making credit card transactions with DraftKings and FanDuel, the two biggest fantasy sports sites.

The ban will last until a decision on the sites’ legality is made by courts, said bank spokeswoman Jennifer Bombardier.

The sites are in a legal dispute with Attorney General Eric Schneiderman, who calls them illegal gambling sites.

The sites argue that their games are based on skill and therefore legal.